NSArray用法大全

main.m

//
//  main.m
//  NSArray
//
//  Created by Rayln Guan on 9/4/13.
//  Copyright (c) 2013 Rayln Guan. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Student.h"

int main(int argc, const char * argv[])
{

    @autoreleasepool {
#pragma mark 数组的基本用法
        NSArray *arr = [NSArray arrayWithObjects:@"a",@"b",@"c",nil];
        
        //得到数组长度
        NSUInteger count = [arr count];
        NSLog(@"%zi", count); //返回3
        
        //返回是否包含字符
        BOOL iscontain = [arr containsObject:@"1"];
        NSLog(@"bool: %i", iscontain); // 返回0
        
        //返回最后的元素
        NSString *last = [arr lastObject];
        NSLog(@"last: %@", last); //返回c
        
        //根据标签返回元素
        NSString *index = [arr objectAtIndex:1];
        NSLog(@"index: %@",index); //返回b
        
        //查找位置
        NSUInteger indexObj = [arr indexOfObject:@"c"];
        NSLog(@"%zi", indexObj); //返回2
        
        //Array在内存中的管理
        Student *stu1 = [[Student alloc] init];
        Student *stu2 = [[Student alloc] init];
        //此处stu1, stu2的retainCount ＝ 1
        NSArray *array = [NSArray arrayWithObjects:stu1, stu2, nil];
        //此处的stu1, stu2的retainCount = 2
        //当stu1, stu2被销毁。
        [stu1 release];
        [stu2 release];
#pragma mark Array的list对象全部调用方法
        //Array的list对象全部调用方法
        [array makeObjectsPerformSelector:@selector(test)];
        [array makeObjectsPerformSelector:@selector(test2:) withObject:@"params1"];
        
#pragma mark 遍历数组
        //遍历数组1
        for (NSUInteger i = 0; i < array.count; i++) {
            NSLog(@"%@", [array objectAtIndex:i]);
        }
        //遍历数组2
        for (Student *stu in array) {
            NSLog(@"forEach--%@", stu);
        }
        //遍历数组3-推荐使用block, 利用block进行for循环调用
        [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
            // obj是当前对象，idx是当前位置, stop是是否停止
            //停止循环遍历
            *stop = YES;
        }];
        //遍历数组4-迭代器遍历
        NSEnumerator *enumer = [array objectEnumerator];
        //NSEnumerator *enumer = [array reverseObjectEnumerator] 获取反序迭代器
        id obj = nil;
        while (obj = [enumer nextObject]) {
            NSLog(@"Enumer-%@:", obj);
        }
        //取得没有被遍历的所有对象
        NSArray *arrayEnum = [enumer allObjects]; //因此这将输出［］，如果在while之前遍历，将是所有对象
        
#pragma mark -
#pragma mark 派生出新的array
        //newArray派生出新的类，而原本的array不受影响
        NSArray *newArray = [array arrayByAddingObject:[[Student alloc] init]];
        NSArray *newArray2 = [array arrayByAddingObjectsFromArray:[NSArray arrayWithObjects:@"a", @"b", nil]];
        //截取范围内的Array
        NSRange range = NSMakeRange(1, 2);
        NSArray *newArray3 = [newArray2 subarrayWithRange:range];
        NSLog(@"%@", newArray3); //返回2个元素
        
#pragma mark 数组的其他用法
        //用一个分隔符把数组拼接成字符串
        NSString *str = [array componentsJoinedByString:@"-"];
        NSLog(@"join:%@", str);
        
        //生成xml文件
        [arr writeToFile:@"/Users/rayln/Desktop/text.xml" atomically:YES];
        
        //从文件读取数据
        NSArray *array1 = [NSArray arrayWithContentsOfFile:@"/Users/rayln/Desktop/text.xml"];
    }
    return 0;
}

Student.h

//
//  Student.h
//  NSArray
//
//  Created by Rayln Guan on 9/4/13.
//  Copyright (c) 2013 Rayln Guan. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Student : NSObject

- (void) test;

- (void) test2:(NSString *)params;
@end

Student.m

//
//  Student.m
//  NSArray
//
//  Created by Rayln Guan on 9/4/13.
//  Copyright (c) 2013 Rayln Guan. All rights reserved.
//

#import "Student.h"

@implementation Student

- (void)test{
    NSLog(@"调用test方法");
}
- (void)test2:(NSString *)params{
    NSLog(@"调用test2方法，参数为%@", params);
}
- (void)dealloc{
    NSLog(@"Student被销毁！");
    [super dealloc];
}
@end