Question

我编写了这段代码，但每次尝试通过System.out.print语句向用户显示输出时都会出错。

代码的目的是检查数组是否是＆＃34;回文＆＃34;。

import java.util.Scanner;
public class u {
public static void main(String[] args) {
    int [] arr = {1,2,3,4,3,2,1};
    int counter1 = 0,counter2 = arr.length-1;
    int x = arr.length/2;
    while (counter1 < x ) {
        if (arr[counter1] == arr [counter2]){
            counter1++;
            counter2--;
        } else {System.out.println(":("); break;}

    } 
    System.out.println("Bingo!");
  }}

Answer 1

如果问题是程序总是打印＆＃34; Bingo！＆＃34;它是因为break只结束了while循环。＆＃34; Bingo！＆＃34; line在while循环之外，所以它仍然会被调用。您可以通过将break更改为return来避免这种情况。您也可以使用标签：

x: {
   while(...) {
        ...
        else break x;
   }
   System.out.println("Bingo!");
}

Answer 2

import java.util.Scanner;
public class u {
public static void main(String[] args) {
boolean d = false; 
int [] arr = {2,9,3,4,4,3,9,2};
int counter1 = 0,counter2 = arr.length-1;
int x = arr.length/2;
while (counter1 < x ) {
    d = false;
    if (arr[counter1] == arr [counter2]){
        counter1++;
        counter2--;
        d = true;
    } else break;
     }
if (d)
System.out.println("Bingo!");
else System.out.println(":(");
}}

我无法向用户显示输出

2 个答案: