数组遍历几种方法

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#import "Blog.h"

@implementation Blog

 

+(Blog *)blog{

    Blog * blog = [[Blog alloc] init];

    return blog;

}

 

-(Blog *)setBlogTitle:(NSString *)title andContent:(NSString *)content{

    _title = title;

    _content = content;

    return self;

}

 

-(NSString *)description{

    return [NSString stringWithFormat:@"blog : title is \"%@\" , and content is \"%@\"", _title,_content ];

}

 

-(void)dealloc{

    NSLog(@"%@被销毁了",self.title);

}

@end

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#pragma mark Array数组的四种遍历方法

void testArray(){

    Blog *blog1 = [[Blog blog] setBlogTitle:@"Love" andContent:@"I love you"];

    Blog *blog2 = [[Blog blog] setBlogTitle:@"Friendship" andContent:@"you are my best friend"];

    NSArray *array = [NSArray arrayWithObjects:@"hello",@"world",blog1,blog2, nil];

     

    //第一种遍历：普通for循环

    long int count = [array count];

    for (int i = 0 ; i < count; i++) {

        NSLog(@"1遍历array: %zi-->%@",i,[array objectAtIndex:i]);

    }

     

    //第二种遍历：快速for循环,需要有外变量i

    int i = 0;

    for (id obj in array) {

        NSLog(@"2遍历array：%zi-->%@",i,[array objectAtIndex:i]);

        i++;

    }

     

    //第三种遍历：OC自带方法enumerateObjectsUsingBlock:

     

    //默认为正序遍历

    [array enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        NSLog(@"3遍历array：%zi-->%@",idx,obj);

    }];

    //NSEnumerationReverse参数为倒序遍历

    [array enumerateObjectsWithOptions:NSEnumerationReverse usingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

        NSLog(@"4倒序遍历array：%zi-->%@",idx,obj);

    }];

     

    //第四种遍历：利用枚举

    NSEnumerator *en = [array objectEnumerator];

    id obj;

    int j = 0 ;

    while (obj = [en nextObject]) {

        NSLog(@"5遍历array：%d-->%@",j,obj);

        j++;

    }

}

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

{

    @autoreleasepool {

        testArray();

    }

    return 0;

}