objective-c数组的七种遍历方法总结

//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，容易引发主线程堵塞，能够另外开辟线程

     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]);

}