发表日期: 2022-03-23 10:45:28 浏览次数:85
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类变量赋值方法
无final修饰,声明时赋值,构造器中赋值,静态语句块或静态方法赋值
有final修饰,声明时赋值,声明与赋值分开可在静态语句块中赋值
public class StaticTest { private static int staticInt = 2; private int random = 2; public StaticTest() { staticInt++; random++; } public static void main(String[] args) { System.out.println("类变量与对象变量的值变化"); StaticTest test = new StaticTest(); System.out.println(" 实例1:staticInt:" + test.staticInt + "----random:" + test.random); StaticTest test2 = new StaticTest(); System.out.println(" 实例2:staticInt:" + test.staticInt + "----random:" + test.random); System.out.println("静态变量赋值"); System.out.println(" 静态语句块起作用:" + A.staticA); A a = new A(); System.out.println(" 构造器起作用:" + a.staticA); a.toChange(); System.out.println(" 静态方法1起作用:" + A.staticA); a.toChange2(); System.out.println(" 静态方法2起作用:" + A.staticA); System.out.println("常量赋值"); System.out.println(" 静态语句赋值:" + B.staticB); }}class A { public static String staticA ="A" ; //静态语句块修改值 static{ staticA ="A1"; } //构造器修改值 public A (){ staticA ="A2"; } //静态方法起作用
public static void toChange(){ staticA ="A3"; } public static void toChange2(){ staticA ="A4"; } }class B { public static final String staticB ; // 声明与赋值分离 static{ staticB ="B"; }}