iOS可变数组添加元素 以及可变数组操作

今天在项目工程中想往可变数组中添加从服务器获取的元素，我用了一下方法：

方法一：

[self.arrM_Data addObjectsFromArray:arr];

方法二：

[self.arrM_DataSource insertObjects:arr atIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(self.arrM_DataSource.count, arr.count)]];

方法三：

for (int i=0; i<arr.count; i++) {

       [self.arrM_DataSource insertObject:[arr objectAtIndex:i] atIndex:self.arrM_DataSource.count];

}

*** Terminating app due to uncaught exception "NSInternalInconsistencyException", reason: "-[__NSCFArray insertObject:atIndex:]: mutating method sent to immutable object"

*** First throw call stack:

(0x281d012 0x1e55e7e 0x281cdeb 0x289d9a5 0x27e1a90 0x27e1893 0x27e1480 0x9d848 0x1e696b0 0x36ecb 0x1e696b0 0x1896035 0x27a0f3f 0x27a096f 0x27c3734 0x27c2f44 0x27c2e1b 0x25717e3 0x2571668 0xd9d65c 0x235a 0x2265)

libc++abi.dylib: terminate called throwing an exception

最后翻看其他网友的解决方案 ，给顺利解决了，贴上解决方案：

NSMutableArray *arrM = [[NSMutableArray alloc] init];

[arrM addObjectsFromArray:self.arrM_Data];

[arrM addObjectsFromArray:arr];

self.arrM_Data = arrM;

[arrM release];