qt5 override
时间: 2023-09-04 14:11:00 浏览: 107
在Qt 5中,`override`关键字用于标记函数是覆盖其基类中的虚函数。它是C++11中的一个关键字,用于明确地表示一个函数是覆盖其基类中的虚函数,这有助于提高代码的可读性和可维护性。
使用`override`关键字的好处在于,如果您尝试覆盖不存在于基类中的虚函数,编译器将会抛出一个错误,从而避免一些常见的错误。
以下是一个简单的示例,演示如何在Qt 5中使用`override`关键字:
```cpp
class Base {
public:
virtual void foo() {}
};
class Derived : public Base {
public:
void foo() override {}
};
```
在这个例子中,`Derived`类覆盖了`Base`类中的`foo`函数,并使用了`override`关键字来明确地表示这一点。
相关问题
qt中 override作用
在Qt中,`override`是C++11中的一个关键字,用于显式地指示一个虚函数是重写基类中的虚函数。它的作用是帮助程序员更好地理解代码,并且在编译时进行类型检查,避免出现不必要的错误。
使用`override`关键字,可以让编译器检查子类中的重写函数是否与基类中的虚函数完全匹配,包括函数名称、参数列表和返回类型。如果不完全匹配,则编译器会发出错误提示,让程序员进行修复。
示例代码:
```cpp
class A {
public:
virtual void foo() {}
};
class B : public A {
public:
void foo() override {}
};
```
在上面的代码中,`B`类重写了`A`类中的`foo`函数,并使用`override`关键字显式地指示了这一点。编译器会检查`B::foo`函数是否与`A::foo`函数完全匹配,如果不匹配则会发出错误提示。
总之,`override`关键字可以提高程序的可读性和健壮性,建议在Qt中的虚函数重写中使用它。
qt override
In Qt, override is a C++11 keyword that allows a derived class to indicate that it is intending to override a virtual function of its base class. When a function is marked with the override keyword, the compiler will check that there is a virtual function in the base class with the same name, and that the function in the derived class has the correct signature (i.e. same return type, parameter types, and constness).
The use of override is considered good practice because it helps to prevent errors and improve code clarity. It makes it clear which functions in a derived class are intended to override base class functions, and helps to catch errors if the signature of the function in the derived class does not match the signature of the function in the base class.
Here is an example of using override in Qt:
```cpp
class MyBaseClass {
public:
virtual void myVirtualFunction(int val) const;
};
class MyDerivedClass : public MyBaseClass {
public:
void myVirtualFunction(int val) const override;
};
void MyDerivedClass::myVirtualFunction(int val) const {
// implementation of the function
}
```
In this example, the MyDerivedClass class is declaring that it intends to override the myVirtualFunction() function from its MyBaseClass base class. The override keyword is used to indicate this intention, and the function in the derived class has the same name, return type, and parameter types as the function in the base class.