Question

静态块外部声明的静态变量与静态块内声明的变量之间有什么区别？（考虑代码段）

代码段如下：

class A{

    static int i = 10;      //line 1

    static { int i = 20;}   //line 2

    public static void main(String[] args) {
        System.out.println(A.i); //output is 10
    }
}

2.如何在第2行访问变量'i'？

Answer 1

 static int i = 10;      //line 1

此处变量i的范围是在类级别。您可以从类中的任何位置访问它。

static { int i = 20;}   //line 2

此处变量i的范围仅限于静态块（如循环变量）。您无法从外部块访问它。

Answer 2

在我看来

第1行中的“i”是全局变量，但在第2行中它是本地，也就是说您无法访问其范围内的变量（这也是问题2的答案）

static {
    int i = 10;
    // this variable's scope only in static {},out of {},you can't access
    // so, if you want access a variable declared in a it's part,you must hold it's refer
    // but, if do this,why not declared it as a class instance member variable or static member variable(just like line 1)
    // generally,static code block is used in initial some class variable or do some prepare work when ClassLoader load it
}

静态块内部声明的静态变量与java中静态块外部的差异

2 个答案: