遍历数组

#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;
}