值传递oppdemo1

public class Demo03 {
    public static void main(String[] args) {
        int a = 1;
        System.out.println(a);//1
        Demo03.change(a);
        System.out.println(a);//1

    }
    //返回值为空null
    public static void change(int a){
        a = 10;
    }
}