数组 NSArray 排序 数组的KVC,KVO

#import <Foundation/Foundation.h>int main(int argc, const char * argv[]) {    @autoreleasepool {        NSArray *array = [NSArray arrayWithObjects:@"你好",@"ios",@"安卓",@"HTML",@"YINGYU",@"迅速", nil];        NSLog(@"第一个元素为%@",[array objectAtIndex:0]);        NSLog(@"索引为1的元素%@",[array objectAtIndex:1]);        NSLog(@"最后一个元素：%@",[array lastObject]);                //索引从3-5的元素组成的新的集合        NSArray *array1 = [array objectsAtIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(3, 3)]];        NSLog(@"%@",array1);                //获取元素在集合中的位置        NSLog(@"HTML的位置为：%ld",[array indexOfObject:@"HTML"]);        //获取元素在集合指定范围中的位置        NSLog(@"在2~4范围内HTML的位置为：%ld",[array indexOfObject:@"HTML" inRange:NSMakeRange(2, 3)]);                        //向数组增加元素        array = [array arrayByAddingObject:@"我是"];        array = [array arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"PHP",@"雄鹰",@"小鸟",@"跳跃", nil]];        for (int i = 0; i<array.count; i++) {            NSLog(@"%@",[array objectAtIndex:i]);             //上面代码可以简化为                //NSLog(@"%@",array[i]);        }                //获取array数组中索引为5~8处的所有元素        NSArray *array2 = [array subarrayWithRange:NSMakeRange(5, 3)];        //将nsarray写入文件        [array2 writeToFile:@"arrayFile.txt" atomically:YES];            }    return 0;}

输出为：

2016-02-29 09:07:49.742 数组[2626:155312] 第一个元素为你好2016-02-29 09:07:49.743 数组[2626:155312] 索引为1的元素ios2016-02-29 09:07:49.743 数组[2626:155312] 最后一个元素：迅速2016-02-29 09:07:49.743 数组[2626:155312] (    HTML,    YINGYU,    "\U8fc5\U901f")2016-02-29 09:07:49.743 数组[2626:155312] HTML的位置为：32016-02-29 09:07:49.743 数组[2626:155312] 在2~4范围内HTML的位置为：32016-02-29 09:07:49.743 数组[2626:155312] 你好2016-02-29 09:07:49.743 数组[2626:155312] ios2016-02-29 09:07:49.743 数组[2626:155312] 安卓2016-02-29 09:07:49.743 数组[2626:155312] HTML2016-02-29 09:07:49.743 数组[2626:155312] YINGYU2016-02-29 09:07:49.743 数组[2626:155312] 迅速2016-02-29 09:07:49.743 数组[2626:155312] 我是2016-02-29 09:07:49.744 数组[2626:155312] PHP2016-02-29 09:07:49.744 数组[2626:155312] 雄鹰2016-02-29 09:07:49.744 数组[2626:155312] 小鸟2016-02-29 09:07:49.744 数组[2626:155312] 跳跃Program ended with exit code: 0

对数组进行排序：

//对数组进行排序#import <Foundation/Foundation.h>//定义一个比较函数NSInteger intSort (id num1,id num2, void *context){    int v1 = [num1 intValue];    int v2 = [num2 intValue];    if (v1<v2)         return NSOrderedAscending;    else if (v1>v2)        return NSOrderedDescending;    else        return NSOrderedSame;}int main(int argc, const char * argv[]) {    @autoreleasepool {        //初始化一个数组对象        NSArray *arr1 =  [NSArray arrayWithObjects:@"OC",@"JAVA",@"HTML",@"Orcal",@"JSP",@"PUSH",@"POP", nil];        //使用集合元素的compare：方法进行排序        arr1 = [arr1 sortedArrayUsingSelector:@selector(compare:)];        NSLog(@"1、%@",arr1);                //继续初始化一个数组对象        NSArray *arr2 = [NSArray arrayWithObjects:[NSNumber numberWithInt:20],[NSNumber numberWithInt:29],[NSNumber numberWithInt:40],[NSNumber numberWithInt:-4],[NSNumber numberWithInt:59] ,nil];        NSLog(@"2、%@",[arr2 sortedArrayUsingSelector:@selector(compare:)]);        //使用sort方法进行排序        arr2 = [arr2 sortedArrayUsingFunction:intSort context:nil];        NSLog(@"3、%@",arr2);        //使用代码块对集合进行元素排序        NSArray *arr3 = [arr2 sortedArrayUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {            //该代码块就是根据集合元素的intValue进行比较            if ([obj1 intValue] > [obj2 intValue]) {                return NSOrderedDescending;            }            if ([obj1 intValue] < [obj2 intValue]) {                return NSOrderedAscending;            }            return NSOrderedSame;        }];        NSLog(@"4、%@",arr3);    }    return 0;}

数组的KVC KVO

程序清单:LYXUser.h

#import <Foundation/Foundation.h>@interface LYXUser : NSObject@property(nonatomic,copy)NSString *name;@property(nonatomic,copy)NSString *pass;-(id)initWithName:(NSString *)name pass:(NSString *)pass;@end

程序清单:LYXUser.m

#import "LYXUser.h"@implementation LYXUser-(id)initWithName:(NSString *)aname pass:(NSString *)apass{    if (self = [super init]) {        _name = aname;        _pass = apass;            }    return self;}@end

程序清单:main.m

#import <Foundation/Foundation.h>#import "LYXUser.h"int main(int argc, const char * argv[]) {    @autoreleasepool {                NSArray *array = [NSArray arrayWithObjects:                          [[LYXUser alloc]initWithName:@"xiaohua" pass:@"afd"],                          [[LYXUser alloc]initWithName:@"xiaolie" pass:@"afd"],                          [[LYXUser alloc]initWithName:@"lili" pass:@"hahah"],                          [[LYXUser alloc]initWithName:@"zhende" pass:@"haoxiang"],nil];        id arr = [array valueForKey:@"name"];        NSLog(@"%@",arr);        [array setValue:@"新名字" forKey:@"name"];        NSLog(@"%@",array);        id arr1 = [array valueForKey:@"name"];        NSLog(@"%@",arr1);            }    return 0;}

打印：

2016-02-29 17:13:51.767 数组[23070:2218035] (    xiaohua,    xiaolie,    lili,    zhende)2016-02-29 17:13:51.767 数组[23070:2218035] (    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57")2016-02-29 17:13:51.767 数组[23070:2218035] (    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57",    "\U65b0\U540d\U5b57")Program ended with exit code: 0