OC_数组

快速枚举: 能快速的遍历数组等容器对象

<code class="hljs  has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">1.都是对容器里的每一个元素的遍历2.为了增加代码的阅读性,避免不必要的错误,尽量让forin的前部分的类型和数组里的元素类型相同</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr = @[@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"杨林"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"刘鑫琪"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李牧燃"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"腾飞"</span>,];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr1 = @[@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"杨林"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"刘鑫琪"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李牧燃"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"腾飞"</span>,];<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr2 = @[@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李珊珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"郭鸿瑞"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"何岸"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"流星雨"</span>];<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr = @[arr1, arr2];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//对arr进行forin遍历</span><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *temp in arr) {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> *str in temp) {        <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);    }}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

<code class="hljs perl has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">Student <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*stu1</span> = [[Student alloc] initWithName:<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@"</span>李牧燃<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"];Student <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*stu2</span> = [[Student alloc] initWithName:<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@"</span>刘鑫琪"</span>];Student <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*stu3</span> = [[Student alloc] initWithName:<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@"</span>刘山山<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"];Student <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*stu4</span> = [[Student alloc] initWithName:<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@"</span>腾飞"</span>];NSArray <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*arr1</span> = <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@[</span>stu1, stu2, stu3];NSArray <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*arr2</span> = <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@[</span>stu4];NSArray <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*arr</span> = <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@[</span>arr1 ,arr2];<span class="hljs-regexp" style="color: rgb(0, 136, 0); box-sizing: border-box;">//</span>便利下数组里每一个学生的名字<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (NSArray <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*temp</span> in arr) {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Student <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">*stu</span> in temp) {        NSLog(<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">@"</span><span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">%@</span><span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">", stu.name);    }}</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>

区别

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *testArr = @[@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"1"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"2"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"3"</span>];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 赋值</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr = [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> alloc]initWithArray:testArr];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 作为一个元素</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> *arr1 = [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSArray</span> alloc] initWithObjects:testArr, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>];</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>

可变数组

可变数组的定义

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 空的可变数组  </span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *arr = [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> alloc] init];<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *arr1 = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> array];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 非空可变数组    </span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *arr2 = [[<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> alloc] initWithObjects:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"傻"</span>, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>];<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *arr3 = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> arrayWithObjects:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"傻"</span>, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>];</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li></ul>

可变数组的一些操作

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;"><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *arr3 = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> arrayWithObjects:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"李"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"珊"</span>, @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"傻"</span>, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 增加一个字符串 其结果是添加到数组的最后一位</span>[arr addObject:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"瓜"</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 移除指定下标的字符串(例如:下标3)</span>[arr removeObjectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 指定下标插入一个字符串(例如:下标3)</span>[arr insertObject:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"大"</span> atIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 替换一个字符串</span>[arr replaceObjectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> withObject:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"刘"</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 交换两个字符串</span>[arr exchangeObjectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> withObjectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSString</span> * str in arr) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, str);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 清空数组</span>[arr removeAllObjects];</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li></ul>

例题

<code class="hljs objectivec has-numbering" style="display: block; padding: 0px; background-color: transparent; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-top-left-radius: 0px; border-top-right-radius: 0px; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; word-wrap: normal; background-position: initial initial; background-repeat: initial initial;">Book *book1 = [Book bookWithName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"西游记"</span> price:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span>];Book *book2 = [Book bookWithName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"红楼梦"</span> price:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">85</span>];Book *book3 = [Book bookWithName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"三国演义"</span> price:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>];Book *book4 = [Book bookWithName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"水浒传"</span> price:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">71</span>];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 四本书放到可变的数组里</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *book = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> arrayWithObjects:book1, book2, book3, book4, <span class="hljs-literal" style="color: rgb(0, 102, 102); box-sizing: border-box;">nil</span>];<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 对数组进行添加操作</span>Book *book5 = [Book bookWithName:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"新华字典"</span> price:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">88</span>];[book addObject:book5];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book * temp in book) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span>);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 对数组进行删除操作</span>[book removeObjectAtIndex:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>];<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book * temp in book) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@"</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span>);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 在数组里根据书名查找对应的书,并且对书的价钱进行修改</span><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book *temp in book) {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> ([temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span> isEqualToString:@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"水浒传"</span>]) {        temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span> = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">98.7</span>;    }}<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book * temp in book) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@, %g"</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span>);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 找到价钱在70 到 100 有多少本书, 然后把符合条件的书放在一个数组里</span><span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> *newBook = [<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSMutableArray</span> array];<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSInteger</span> num = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>;<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book *temp in book) {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span> >= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">70</span> && temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span> <= <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>) {        num++;        [newBook addObject:temp];    }}<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%ld"</span>, num);<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book *temp in newBook) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@ %g"</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span>);}<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 找到价格是100的书,把书名改成论语</span><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book *temp in book) {    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span> == <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">100</span>) {        temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span> = @<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"论语"</span>;    }}<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">for</span> (Book *temp in book) {    <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">NSLog</span>(@<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"%@ %g"</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.name</span>, temp<span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">.price</span>);}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; background-color: rgb(238, 238, 238); top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right;"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li><li style="box-sizing: border-box; padding: 0px 5px;">25</li><li style="box-sizing: border-box; padding: 0px 5px;">26</li><li style="box-sizing: border-box; padding: 0px 5px;">27</li><li style="box-sizing: border-box; padding: 0px 5px;">28</li><li style="box-sizing: border-box; padding: 0px 5px;">29</li><li style="box-sizing: border-box; padding: 0px 5px;">30</li><li style="box-sizing: border-box; padding: 0px 5px;">31</li><li style="box-sizing: border-box; padding: 0px 5px;">32</li><li style="box-sizing: border-box; padding: 0px 5px;">33</li><li style="box-sizing: border-box; padding: 0px 5px;">34</li><li style="box-sizing: border-box; padding: 0px 5px;">35</li><li style="box-sizing: border-box; padding: 0px 5px;">36</li><li style="box-sizing: border-box; padding: 0px 5px;">37</li><li style="box-sizing: border-box; padding: 0px 5px;">38</li><li style="box-sizing: border-box; padding: 0px 5px;">39</li><li style="box-sizing: border-box; padding: 0px 5px;">40</li><li style="box-sizing: border-box; padding: 0px 5px;">41</li><li style="box-sizing: border-box; padding: 0px 5px;">42</li><li style="box-sizing: border-box; padding: 0px 5px;">43</li><li style="box-sizing: border-box; padding: 0px 5px;">44</li><li style="box-sizing: border-box; padding: 0px 5px;">45</li><li style="box-sizing: border-box; padding: 0px 5px;">46</li><li style="box-sizing: border-box; padding: 0px 5px;">47</li><li style="box-sizing: border-box; padding: 0px 5px;">48</li><li style="box-sizing: border-box; padding: 0px 5px;">49</li><li style="box-sizing: border-box; padding: 0px 5px;">50</li><li style="box-sizing: border-box; padding: 0px 5px;">51</li><li style="box-sizing: border-box; padding: 0px 5px;">52</li><li style="box-sizing: border-box; padding: 0px 5px;">53</li><li style="box-sizing: border-box; padding: 0px 5px;">54</li><li style="box-sizing: border-box; padding: 0px 5px;">55</li><li style="box-sizing: border-box; padding: 0px 5px;">56</li><li style="box-sizing: border-box; padding: 0px 5px;">57</li><li style="box-sizing: border-box; padding: 0px 5px;">58</li></ul>