ios 遍历数组的方法

//第一种
[arr enumerateObjectsUsingBlock: ^(id obj, NSUInteger idx, BOOL *stop){
    NSLog(@"%ld,%@",idx,[arr objectAtIndex:idx]);
}];
//第二种
dispatch_apply([arr count], dispatch_get_global_queue(0, 0), ^(size_t index){//并行
    NSLog(@"%ld,%@",index,[arr objectAtIndex:index]);
});
//第三种
dispatch_apply([arr count], dispatch_get_main_queue(), ^(size_t index){//串行，容易引起主线程堵塞，可以另外开辟线程
    NSLog(@"%ld,%@",index,[arr objectAtIndex:index]);
});
//第四种
for (NSString*str in arr) {
     NSLog(@"%@",str);
}
//第五种，do-while
int i = 0;
do {
    NSLog(@"%@",[arr objectAtIndex:i]);
    i++;
} while (i<[arr count]);
 
//第六种，while-do
int j = 0;
while (j<[arr count]) {
    NSLog(@"%@",[arr objectAtIndex:j]);
    j++;
}
//第七种，普通for循环
for (int m = 0; m<[arr count]; m++) {
    NSLog(@"%@",[arr objectAtIndex:m]);
}


//第八中
NSEnumerator *enumerator = [langArray objectEnumerator];  
id object;  
while ((object = [enumerator nextObject]) != nil) {  
     NSLog(@"langArray=%@", object);  
}