Java变量范围

Question

当一个变量初始化无论是在本地范围内以及全球范围内，我们如何利用全球范围内不使用this在同级别的关键字？

Answer 1

class MyClass{
    int i;//1
    public void myMethod(){
        i = 10;//referring to 1    
    }

    public void myMethod(int i){//2
        i = 10;//referring to 2
        this.i = 10 //refering to 1    
    }    
}  

Also See :

• Shadowing Declarations
• what-is-variable-shadowing-used-for-in-a-java-class

Answer 2

如果不使用this它将始终是局部变量。

Answer 3

It is impossible without this. The phenomenon is called variable hiding .

Answer 4

If you are scoping the variable reference with this it will always point to the instance variable.

If a method declares a local variable that has the same name as a class-level variable, the former will 'shadow' the latter. To access the class-level variable from inside the method body, use the this keyword.

Answer 5

public class VariableScope {

    int i=12;// Global
    public VariableScope(int i){// local

        System.out.println("local :"+i);
        System.out.println("Global :"+getGlobal());
    }
    public int getGlobal(){
        return i;
    }
}