图片数组的互相转换

//字符串转变为数组1
NSMutableString * str=[[ NSMutableString alloc]initWithFormat:@ "1,1,1,1,1,1" ];
//字符串转变为数组2
NSMutableArray * array=[ NSMutableArray arrayWithArray:[str   componentsSeparatedByString:@ "," ]];
//替换数组中的某个值
[array replaceObjectAtIndex:4 withObject:@ "2" ];
//把数组转换成字符串
NSString *ns=[array componentsJoinedByString:@ "," ];