java - 如何从方法变量中清除以前存储的值

Question

每当我打印 sev 的值时，它也会首先打印 rev，为什么我缺少 rev i/p 456，它按预期正确给出了 654 但在 789 的下一步中，它给出 456987 我怎样才能得到正确答案

    public static void main(String []args){
    int num1=0;
        int num2 =0;
        int rev = namo(num1);
        System.out.println(rev);
        int sev = namo(num2);
        System.out.println(sev);



    }    
    static  Scanner sc = new Scanner(System.in);
    static int rev_num = 0; 
    public static int namo(int m) {
            m = sc.nextInt();
           while (m!= 0) {
               rev_num = rev_num * 10 + m % 10;
               m = m / 10;
           }
           return rev_num;
           }

       }

Answer 1

rev_num 是静态变量，不是方法变量，因此需要在方法内将其初始化为零。
有关静态变量的更多信息:https://beginnersbook.com/2013/05/static-variable/

    public static int namo(int m) {
    rev_num = 0;
    m = sc.nextInt();
    while (m!= 0) {
        rev_num = rev_num * 10 + m % 10;
        m = m / 10;
    }
    return rev_num;
}

而不是声明，

    static int rev_num = 0; 

在外部方法中，您可以声明内部方法本身，

public static int namo(int m) {
    int rev_num = 0;
    m = sc.nextInt();
    while (m!= 0) {
        rev_num = rev_num * 10 + m % 10;
        m = m / 10;
    }
    return rev_num;
}