Question

我不明白我该如何让这个程序停止。基本上它要我做的是当我输入-1时程序关闭。我只是无法弄清楚如何。哦！瑞典的“sida”意味着一面。不知道是否有帮助！在这里你们的帮助下会很棒！

import java.util.Scanner;
public class triangle
{

//Triangle is going up
public static void triangelUpp(int sida)
{

    for(int i = 0; i <= sida; i++)
    {
        for(int j = 1; j <= i; j++)
        System.out.print("*");
        System.out.println();
    }       
}


//Triangle going down
public static void triangelNed(int sida)
{

    for(int i = 0; i <= sida; i++)
    {
        for(int j = 1; j <= sida - i; j++)
        System.out.print("*");
        System.out.println();
    }       
}


public static void main(String[] args)
{

    //Variables 
    Scanner keyboard = new Scanner(System.in);
    int vinkel = 0;
    int sida = 0;


    //Rules
    while(sida !=-1)
    {
        if(vinkel == 0)
            triangelNed(sida);

        else if(vinkel == 1)
            triangelUpp(sida);

    System.out.println("Write the length of the triangle and end with -1");
    sida = keyboard.nextInt();

    System.out.println("Is the angle going to be up(1) or down?(0)");
    vinkel = keyboard.nextInt();

    }

}

}

Answer 1

最简单的方法：将while-loop更改为while(true)，然后在指定sida之后：if (sida < 0) { break; }

换句话说：

while(true) {
    //some logic here...
    sida = keyboard.nextInt();
    //if (sida < 0) {
    //since you don't like the regular approach, changing it to fit your odd needs
    if (sida == -1) {
        //breaks the while loop
        break;
    }
    //rest of code...
}

使用System.exit(0)只会杀死进程，显示示例

while(true) {
    //code here...
    //same here
    //if (sida < 0) {
    if (sida == -1) {
        //comment/uncomment the options to see the program behavior
        //using this, the message after the while loop will be printed
        break;
        //using this, the message after the while loop won't be printed
        //System.exit(0);
    }
}
System.out.println("Thanks! See ya later");

Answer 2

与问题无关，编程时最好的办法是用英语编写变量和注释。

但休息确实是最好的方法。虽然我会检查它是否等于-1而不是小于0.（这是Luigi Mendoza答案的补充）

if (sida == -1) {

而不是

if (sida < 0) {

Answer 3

退出您可以使用的程序 system.exit（0）;

新手需要帮助如何在Java中退出我的程序

3 个答案: