objective-c数组的四种遍历方法总结

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;
}