objective-c数组的四种遍历方法总结

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Blog类：

01#import "Blog.h"
02@implementation Blog
03 
04+(Blog *)blog{
05    Blog * blog = [[Blog alloc] init];
06    return blog;
07}
08 
09-(Blog *)setBlogTitle:(NSString *)title andContent:(NSString *)content{
10    _title = title;
11    _content = content;
12    return self;
13}
14 
15-(NSString *)description{
16    return [NSString stringWithFormat:@"blog : title is \"%@\" , and content is \"%@\"", _title,_content ];
17}
18 
19-(void)dealloc{
20    NSLog(@"%@被销毁了",self.title);
21}
22@end

主函数：

01#pragma mark Array数组的四种遍历方法
02void testArray(){
03    Blog *blog1 = [[Blog blog] setBlogTitle:@"Love" andContent:@"I love you"];
04    Blog *blog2 = [[Blog blog] setBlogTitle:@"Friendship" andContent:@"you are my best friend"];
05    NSArray *array = [NSArray arrayWithObjects:@"hello",@"world",blog1,blog2, nil];
06     
07    //第一种遍历：普通for循环
08    long int count = [array count];
09    for (int i = 0 ; i < count; i++) {
10        NSLog(@"1遍历array: %zi-->%@",i,[array objectAtIndex:i]);
11    }
12     
13    //第二种遍历：快速for循环,需要有外变量i
14    int i = 0;
15    for (id obj in array) {
16        NSLog(@"2遍历array：%zi-->%@",i,[array objectAtIndex:i]);
17        i++;
18    }
19     
20    //第三种遍历：OC自带方法enumerateObjectsUsingBlock:
21     
22    //默认为正序遍历
23    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
24        NSLog(@"3遍历array：%zi-->%@",idx,obj);
25    }];
26    //NSEnumerationReverse参数为倒序遍历
27    [array enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
28        NSLog(@"4倒序遍历array：%zi-->%@",idx,obj);
29    }];
30     
31    //第四种遍历：利用枚举
32    NSEnumerator *en = [array objectEnumerator];
33    id obj;
34    int j = 0 ;
35    while (obj = [en nextObject]) {
36        NSLog(@"5遍历array：%d-->%@",j,obj);
37        j++;
38    }
39}
40int main(int argc, const char * argv[])
41{
42    @autoreleasepool {
43        testArray();
44    }
45    return 0;
46}

结果：

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