int x {}之间有区别吗？并且int x = 0 ;? [英] Is there a difference between int x{}; and int x = 0;?

问题描述

我知道 int x {}; 是一种默认初始化，但它与编写 int x = 0完全一样; ？

I understood that int x{}; is a kind of default-initialization, but is it exactly the same as writing int x = 0; ?

推荐答案

在这种情况下，结果是相同的。

The result is same in this case.

int x {}; 是一种默认初始化

不完全是。请参见默认初始化。

int x {}; 是值初始化（自C ++ 11起），

int x{}; is value initialization (since C++11),

这是使用空初始化程序构造变量时执行的初始化

This is the initialization performed when a variable is constructed with an empty initializer.

在这种情况下，值初始化的影响（即类类型和数组类型都不是）：

And the effects of value initialization in this case (i.e. neither class type nor array type) are:

4）否则，对象将零初始化。

最后，在这种情况下，零初始化的效果是：

Finally the effects of zero initialization in this case are:

如果T是标量类型，则对象的初始值为积分
常量零

另一方面， int x = 0; 是复制初始化； x 初始化为值 0 。

On the other hand, int x = 0; is copy initialization; x is initialized with the value 0.

As @PaulR提到，有一个区别，只有c ++ 11支持 int x {}; ，而 int x = 0 没有这样的限制。

As @PaulR mentioned, there's a difference that int x{}; is only supported from c++11, while int x = 0 has not such restriction.

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