java private
时间: 2023-11-13 12:32:24 浏览: 33
"private"是Java中的一个访问修饰符,它可以用来修饰类的成员变量和方法。将一个成员变量或方法声明为private,意味着它只能在类的内部访问,而无法被类的外部代码访问。这样可以保证类的内部实现细节不会被外部代码所干扰,同时也可以提高代码的安全性和可维护性。在Java中,private是访问权限最严格的修饰符之一。
相关问题
java private调用
在Java中,private方法和变量只能在同一个类中访问,无法在其他类中调用。如果需要在其他类中调用private方法,可以使用public方法或者protected方法来间接调用private方法。例如:
```java
public class A {
private void privateMethod() {
System.out.println("This is a private method!");
}
public void publicMethod() {
System.out.println("This is a public method!");
privateMethod(); // 调用私有方法
}
}
public class B {
public static void main(String[] args) {
A a = new A();
a.publicMethod(); // 调用公有方法,间接调用私有方法
}
}
```
在上面的例子中,类A中的私有方法privateMethod()无法在类B中直接调用。但是,类A中的公有方法publicMethod()可以在类B中调用,而且publicMethod()中又调用了privateMethod(),从而间接调用了私有方法。
java private protected
Java has four access modifiers for classes, methods, and variables:
1. Public: The public access modifier means that the class, method, or variable can be accessed from anywhere in the program.
2. Private: The private access modifier means that the class, method, or variable can only be accessed within the same class.
3. Protected: The protected access modifier means that the class, method, or variable can only be accessed within the same class, or by a subclass in a different package.
4. Default: If no access modifier is specified, the class, method, or variable has default access, which means it can only be accessed within the same package.
Private members can only be accessed within the same class. This means that any other class cannot access the private member, even if it is in the same package.
Protected members can be accessed within the same class, as well as by a subclass in a different package. This means that any class that extends the class with the protected member can access it.
In general, it is best practice to use the most restrictive access modifier that still allows the necessary access to the member. This helps to ensure that the code is secure and maintainable.