Objective C - 需要左值作为赋值的左操作数
我收到此代码的错误（需要左值作为赋值的左操作数）：
[[addAlertViewController alertsArray] = [NSMutableArray arrayWithObjects:nil] retain];
如何修复它？
I get the error (Lvalue required as left operand of assignment) for this code:
[[addAlertViewController alertsArray] = [NSMutableArray arrayWithObjects:nil] retain];
How can I fix it?
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了解左值和右值有助于破译编译器警告。左值是要被赋值的东西，右值是可以进行赋值的东西。 有关维基百科的更多信息
右值也可以是左值，例如a = b = c（其中 c 是左值 b 的右值，但 b 是左值 a 的右值）。
每当您看到“需要左值”，然后查看 = 运算符的左侧时，就会发现那里有错误。
Knowing what an lvalue and rvalue will help when deciphering compiler warnings. A lvalue is something that will be assigned and a rvalue is something that can do the assigning. More info on wikipedia
An rvalue can also be a lvalue, like in the case of a = b = c (where c is an rvalue to lvalue b, but then b is a rvalue to the lvalue a).
anytime you see "lvalue required" then look on the left of the = operator, there is an error there.
适当的代码如下：
请注意，您已在
addAlertViewController的类的@interface中声明：并在您的实现文件
而且..我同意@taskinoor，RTFM。
The appropriate Code is as follows:
Be careful that you have declared in your
@interfaceofaddAlertViewController's Class:And in your implementation file
And.. I'll agree with @taskinoor, RTFM.