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ios
2016-02-29 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：3
2016-02-29 09:07:49.743 数组[2626:155312] 在2~4范围内HTML的位置为：3
2016-02-29 09:07:49.743 数组[2626:155312] 你好
2016-02-29 09:07:49.743 数组[2626:155312] ios
2016-02-29 09:07:49.743 数组[2626:155312] 安卓
2016-02-29 09:07:49.743 数组[2626:155312] HTML
2016-02-29 09:07:49.743 数组[2626:155312] YINGYU
2016-02-29 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] PHP
2016-02-29 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