objective-c数组的四种遍历方法总结

转自：http://blog.youkuaiyun.com/liulushi_1988/article/details/14105137

 objective-c 语言 数组遍历的4种方式：1、普通for循环；2、快速for循环；3、特性block方法；4、枚举方法。

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

02	void 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

}

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

41

{

42	@autoreleasepool {

43	testArray();

44

}

45

return 0;

46

}