Question

我有一个程序，最初将两个数字传递给一个方法并返回更高的数字。我得到了所以我决定扩展到该程序，并希望程序向用户询问2个数字。我有两个问题，我无法弄清楚。首先是说我的变量i和j没有被初始化。第二个是程序循环3次。有人可以给我任何帮助。我来自c＃谢谢。

package javabook;
import java.util.Scanner;

public class Chapter5 {

    public static void main(String[] args) 
    {
        int i;
        int j;
        int k = max(num1(i),num2(j));
        //Scanner input = new Scanner(System.in);       
        num1(i);
        num2(j);

        System.out.print("The maximum between " + num1(i) + " and " + num2(j) + " is " +k);
    }

    //Return the max between two numbers
    public static int max(int num1, int num2)
    {
        int result;

        if (num1>num2)
            result = num1;
        else
            result = num2;      
        return result;      
    }//End Max Method


    public static int num1(int i)
    {
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the first number: ");
        input.nextInt();
        input.close();
        return i;
    }//End num1 method
    public static int num2(int j)
    {
        Scanner input = new Scanner(System.in);
        System.out.print("Please enter the second number: ");
        input.nextInt();
        input.close();
        return j;
    }//end num2 method


}

Answer 1

这里：

    int i;
    int j;   <---creates the var, but doesn't initialize it
    int k = max(num1(i),num2(j));
                             ^---using the var, without having initialized it

即使是简单的

j = 0;

会有所帮助。

Answer 2

局部变量与全局声明的变量没有相同的值，因此您必须指定一些值才能使用它们。全局变量int默认值为0。

use strict;
use warnings;

my $flag =0;

my @locations= (
  "/path/with/foo/HELLO",
  "/path/with/foo/def-abc-addons.install",
  "/path/with/foo/def-abc-addons.lintian-overrides",
  "/path/with/foo/def-abc-addons.postrm",
  "/abc/def/ggfg",
  "/frgrg/hjytj/dgth",
);

foreach my $location(@locations){
   if ($location =~ m/\/foo\/HELLO/) {
       print 'match';
       $flag=1;
    } else {
      print 'no match';
      $flag=0
    } 
 }

本地变量可能尚未初始化并且循环

2 个答案: