我有一个数组，如下例所示:[{"lx":144,"ly":57,"mx":144,"my":56},{"lx":321,"ly":-4,"mx":298,"my":16}]我想给每个元素设置一半的值。简而言之，我想要如下内容。[{"lx":72,"ly":28.5,"mx":72,"my":28},{"lx":160.5,"ly":-2,"mx":149,"my":8}]我正在使用以下代码:NSMutableArray*tempArray=[NSMutableArrayarrayWithCapacity:0];for(inti=0;i我用一个循环完成了它，它在处理少量数据时工作正常。但