NSArray - 数组

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//
//  main.m
//  OC04-task-07
//
//  Created by Xin the Great on 15-1-24.
//  Copyright (c) 2015年 Xin the Great. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "NSArray+Log.h"
#import "Person.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        
        ///////////////NSArray - 数组///////////////
        //数组的创建, 使用alloc init创建和使用类方法创建功效是一样的，但是内存管理上不同
        NSArray *arr1 = [[NSArray alloc] initWithObjects:@"1",@"2", nil];
        NSLog(@"arr1 is %@",arr1);
        //类方法创建
        NSArray *arr2 = [NSArray arrayWithObjects:@"11",@"22", nil];
        NSLog(@"arr2 is %@",arr2);
        //此初始化方法使arr3只有一个元素
        NSArray *arr3 = [NSArray arrayWithObject:@"我们在学IOS"];
        NSLog(@"arr3 is %@",arr3);
        
        //创建一个人的对象
        Person *jack = [[Person alloc] init];
        jack.name = @"jack";
        jack.age = 30;
        NSArray *arr4 = [NSArray arrayWithObject:jack];
        NSLog(@"arr4 is %@",arr4);
        
        //通过已有的数组构造一个新的数组
        NSArray *newArray = [NSArray arrayWithArray:arr2];
        NSLog(@"newArray is %@",newArray);


        
        //数组的访问
        //objectAtIndex: 根据下标取出元素,如果下标越界，程序崩溃（crash）
        Person *jack1 = [arr4 objectAtIndex:0];
        NSLog(@"jack1 is %@",jack1);
        
        //通过元素取下标, 如果没有找到，则返回NSNotFound
        NSArray *arr5 = [NSArray arrayWithObjects:@"1",@"2",jack, nil];
//        NSInteger index = [arr5 indexOfObject:jack];
//        NSLog(@"index is %ld", index);
        NSInteger index = [arr5 indexOfObject:@"123"];
        NSLog(@"index is %ld", index);
        
        //求数组的长度
        NSInteger count = [arr5 count];
        NSLog(@"count is %ld", count);
        
        //判断数组中是否存在某一个元素,
        BOOL isTrue = [arr5 containsObject:@"123"];
        NSLog(@"isTrue is %d",isTrue);
        
        //将数组变成一个字符串
        NSArray *arr6 = [NSArray arrayWithObjects:@"1",@"2",@"3",@"4",@"5", nil];
        NSString *str = [arr6 componentsJoinedByString:@"-"];
        NSLog(@"str is %@",str);
        //将字符串分割成数组
        NSArray *arr7 = [str componentsSeparatedByString:@"-"];
        NSLog(@"arr7 is %@",arr7);
        
        //获取第一个元素和最后一个元素
        NSString *firstStr = arr7[0];
        NSLog(@"firstStr is %@",firstStr);
//        NSString *lastStr = arr7[arr7.count - 1];
        //最后一个元素
        NSString *lastStr = [arr7 lastObject];
        NSLog(@"lastStr is %@",lastStr);

        //简单写法
        NSArray *arr8 = @[jack, @"2"];
        
        NSString *value = arr8[0];
        NSLog(@"value is %@",value);
        
    }
    return 0;
}

NSArray - 数组

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原文地址：http://blog.csdn.net/zuojx1013/article/details/43163531