c++ - int a = int(); 这个int()是什么用法呢？

Question

下面这段代码

int a = int();
cout<<a<<endl;

输出是0;

我想知道这个int()是什么用法。或者您可以告诉我用什么名词可以搜索到这个内容，我想具体得了解一下。

Answer 1

Keywords: constructor

For a type, the type name itself is the constructor of the type
For example, there is a class

class A {
    ...
};

Then A() is the constructor of type A. Using A() you can get a variable of type A.
int is a built-in type, so int() calls the constructor of the int type and returns an int variable.