IOS开发之OC篇（3）—— NSArray、NSMutableArray

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版本

Xcode 8.2.1

一、不可变数组NSArray

老规矩，先贴上知识点，再打个例子和举个比方。

//使用arrayWithObjects创建NSArray

NSArray *arr = [NSArray arrayWithObjects:@"abc",@"def",@"123",nil];

// NSArray *arr = [[NSArray alloc] initWithObjects:@"111",@"ddd",@"234",nil];

//使用arrayWithArray创建NSArray

NSArray *arr1 = [NSArray arrayWithArray:arr];

// NSArray *arr1 = [[NSArray alloc]initWithArray:arr];

//使用@创建NSArray,只能创建不可变数组

NSArray *arr2 = @[@"aaaa",@"bbb",@"ddddd"];

NSLog(@"arr2 = %@",arr2);

//返回元素个数

NSLog(@"arr2 count = %ld",[arr2 count]);

//返回指定位置id

NSString *str0 = [arr2 objectAtIndex:2];

NSLog(@"str0 = %@",str0);

//访问数组的最后一个元素

NSString *str = [arr2 lastObject];

NSLog(@"str = %@",str);

//访问数组的第一个元素

NSString *str1 = [arr firstObject];

NSLog(@"str1 = %@",str1);

//判断数组内是否含有某一个对象

if([arr containsObject:@"123"]) {

NSLog(@"含有此对象");

}

//获取某个对象在数组中的下标值

NSUInteger index = [arr indexOfObject:@"123"];

//数组的遍历

for(NSInteger i =0;i < [arr count]; i++) {

NSLog(@"arr[%ld] = %@",i,arr[i]);

}

//快速枚举法(快速遍历)

for(id objin arr) {

NSLog(@"obj = %@",obj);

}

int main(int argc, char * argv[]) {        //使用arrayWithObjects创建NSArray    NSArray *arr = [NSArray arrayWithObjects:@"ABC",@"DEF",@"GHI",nil];        //NSArray *arr = [[NSArray alloc] initWithObjects:@"ABC",@"DEF",@"GHI",nil];    NSLog(@"arr = %@",arr);        //使用arrayWithArray创建NSArray    NSArray *arr1 = [NSArray arrayWithArray:arr];        //NSArray *arr1 = [[NSArray alloc]initWithArray:arr];    NSLog(@"arr1 = %@",arr1);        //使用@创建NSArray,只能创建不可变数组    NSArray *arr2 = @[@"123",@"456",@"789"];    NSLog(@"arr2 = %@",arr2);        //返回元素个数    NSLog(@"arr count = %ld",[arr count]);        //返回指定位置id    NSString *str = [arr objectAtIndex:1];    NSLog(@"str = %@",str);        //访问数组的第一个元素    NSString *strF = [arr firstObject];    NSLog(@"strF = %@",strF);        //访问数组的最后一个元素    NSString *strL = [arr lastObject];    NSLog(@"strL = %@",strL);        //判断数组内是否含有某一个对象    if ([arr2 containsObject:@"456"]) {        NSLog(@"数组arr2内含有对象456");    }        //获取某个对象在数组中的下标值    NSUInteger index = [arr indexOfObject:@"ABC"];    NSLog(@"ABC下标值为%ld",index);        //数组的遍历    for (NSInteger i = 0; i < [arr count]; i++) {        NSLog(@"arr[%ld] = %@",i,arr[i]);    }        //快速枚举法(快速遍历)    for (id arr2Q in arr2) {        NSLog(@"arr2Q = %@",arr2Q);    }}

输出结果：

二、可变数组NSMutableArray

//实例化一个空的可变数组

NSMutableArray *nsarr = [[NSMutableArray alloc]init];

//添加一个元素

[nsarr addObject:@"ONE"];

NSLog(@"nsarr = %@",nsarr);

//添加多个元素

[nsarr addObjectsFromArray:@[@"ONE",@"TWO",@"THREE"]];

NSLog(@"nsarr = %@",nsarr);

//插入元素

[nsarr insertObject:@"Two" atIndex:1];

NSLog(@"nsarr = %@",nsarr);

//替换元素

[nsarr replaceObjectAtIndex:0 withObject:@"1"];

NSLog(@"nsarr = %@",nsarr);

//查询元素

NSString *result = [nsarr objectAtIndex:1];//arr[1]

NSLog(@"result = %@",result);

//删除指定元素

[nsarr removeObject:@"ONE"];

NSLog(@"nsarr = %@",nsarr);

//删除指定下标的元素

[nsarr removeObjectAtIndex:2];

NSLog(@"nsarr = %@",nsarr);

//删除最后一个元素

[nsarr removeLastObject];

NSLog(@"nsarr = %@",nsarr);

//删除所有元素

[nsarr removeAllObjects];

NSLog(@"nsarr = %@",nsarr);

//删除数组中含有的所有元素

[nsarr removeObjectsInArray:@[@"1",@"THREE"]];

//交换元素

NSMutableArray *nsarr1 = [NSMutableArray arrayWithObjects:@"1",@"2",@"3",nil];

[nsarr1 exchangeObjectAtIndex:1 withObjectAtIndex:2];

NSLog(@"nsarr1 = %@",nsarr1);

//切割字符串

NSString *str3 = @"I am a super man + beautiful, yeah!";

//用指定的字符串进行切割

NSArray *rArr = [str3 componentsSeparatedByString:@" "];

NSLog(@"rArr = %@",rArr);

//实例化一个字符集合

NSCharacterSet *set = [NSCharacterSet characterSetWithCharactersInString:@" ,+"];

//按照字符集合所提供的字符进行切割

NSArray *rArr2 = [str3 componentsSeparatedByCharactersInSet:set];

NSLog(@"rArr2 = %@",rArr2);

//拼接数组内的字符串

NSString *str2 = [rArr2 componentsJoinedByString:@"-"];

NSLog(@"str2 = %@",str2);

//按照ASCII码大小进行排序,SEL:方法选择器(储存一个方法名)

NSMutableArray *arr3 = [NSMutableArray arrayWithObjects:@"B",@"A",@"C",@"Z",nil];

[arr3 sortedArrayUsingSelector:@selector(compare:)];//方法选择器

//按三个人年龄大小排序

Person *per0 = [[Person alloc]initWith:18];

Person *per1 = [[Person alloc]initWith:6];

Person *per2 = [[Person alloc]initWith:60];

NSMutableArray *perArr = [[NSMutableArray alloc]initWithObjects:per0,per1,per2,nil];

//compareAge提供一个排序方法，看按什么方式排序

NSArray *resultPerArr = [perArr sortedArrayUsingSelector:@selector(compareAge:)];

int main(int argc, char * argv[]) {        //实例化一个空的可变数组    NSMutableArray *arr = [[NSMutableArray alloc]init];        //添加一个元素    [arr addObject:@"he"];    NSLog(@"arr = %@",arr);        //添加多个元素    [arr addObjectsFromArray:@[@"is",@"Chinese"]];    NSLog(@"arr = %@",arr);    //插入元素    [arr insertObject:@"not" atIndex:2];    NSLog(@"arr = %@",arr);        //以arrayWithArray创建arr1    NSMutableArray  *arr1 = [NSMutableArray arrayWithArray:arr];    //替换元素    [arr replaceObjectAtIndex:3 withObject:@"Japanese"];    NSLog(@"arr = %@",arr);    //查询元素    NSString *result = [arr objectAtIndex:0];    NSLog(@"arr[0] = %@",result);    //删除指定元素    [arr removeObject:@"not"];    NSLog(@"arr = %@",arr);    //删除指定下标的元素    [arr removeObjectAtIndex:1];    NSLog(@"arr = %@",arr);    //删除最后一个元素    [arr removeLastObject];    NSLog(@"arr = %@",arr);    //删除所有元素    [arr removeAllObjects];    NSLog(@"arr = %@",arr);    //删除数组中含有的所有元素    [arr1 removeObjectsInArray:@[@"not",@"is"]];    NSLog(@"arr1 = %@",arr1);    //交换元素    [arr1 exchangeObjectAtIndex:0 withObjectAtIndex:1];    NSLog(@"arr1 = %@",arr1);    //切割字符串    NSString *str1 = @"I am,a super man!";    //用指定的字符串进行切割    NSArray *cutArr = [str1 componentsSeparatedByString:@","];    NSLog(@"cutArr = %@",cutArr);    //实例化一个字符集合    NSCharacterSet *set = [NSCharacterSet  characterSetWithCharactersInString:@"super "];    //按照字符集合所提供的字符进行切割    NSArray *cutArr2 = [str1 componentsSeparatedByCharactersInSet:set];    NSLog(@"cutArr2 = %@",cutArr2);    //拼接数组内的字符串    NSString *str2 = [cutArr2 componentsJoinedByString:@"-"];    NSLog(@"str2 = %@",str2); /*    //按照ASCII码大小进行排序,SEL:方法选择器(储存一个方法名)    NSMutableArray *arr3 = [NSMutableArray arrayWithObjects:@"B",@"A",@"C",@"Z",nil];    [arr3 sortedArrayUsingSelector:@selector(compare:)]; //方法选择器        //按三个人年龄大小排序    Person *per0 = [[Person alloc]initWith:18];    Person *per1 = [[Person alloc]initWith:6];    Person *per2 = [[Person alloc]initWith:60];    NSMutableArray *perArr = [[NSMutableArray alloc]initWithObjects:per0,per1,per2,nil];    //compareAge提供一个排序方法，看按什么方式排序    NSArray *resultPerArr = [perArr sortedArrayUsingSelector:@selector(compareAge:)]; */}

输出结果：

注：NSArray和NSMutableArray只能存储OC对象。

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