java - 为什么我的网格没有从 'O' 更新到 'S'(数组)

Question

基本上，我正在尝试创建一个程序，当用户在扫描仪中输入坐标时，我的网格从“O”更改为“S”。对我来说，这是合乎逻辑的方法，我是java新手，想知道我的代码是否有错误，扫描仪正在挑衅地工作，就好像我尝试打印 x 一样，它会显示用户输入的 int 。提前谢谢您。

 import java.util.Scanner;
 public class TheGame {
 public static void main(String[] args) { {

 System.out.println ("Players Board");


char [][] grid = new char [10][10];
//FILL GRID//
for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)

{

    for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
    {
        grid[outerLoopValue][innerLoopValue]='O';
    }

    }
   //END OF FILL GRID//
    //DRAW GRID//
   for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)
    {

    System.out.println("");
    for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
    {
    System.out.print(grid[outerLoopValue][innerLoopValue]+"  ");
    }
    }
Scanner sc =new Scanner(System.in);
System.out.println("Please Choose the Co-ordinates of your first ship");
System.out.println("X = ");
int x = sc.nextInt();
System.out.println("Y = ");
int y = sc.nextInt(); 

grid[x][y] = 'S';  

Answer 1

网格确实发生了变化，但是您在用户输入后没有打印网格，因此您没有看到网格发生变化。

我建议你提取一个打印网格的方法。

public static void printGrid(char[][] grid) {
    for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)
    {
        System.out.println("");
        for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
        {
            System.out.print(grid[outerLoopValue][innerLoopValue]+"  ");
        }
    }
}

然后，在用户输入内容之前和之后调用此方法:

System.out.println ("Players Board");


char [][] grid = new char [10][10];
//FILL GRID//
for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)
{

    for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
    {
        grid[outerLoopValue][innerLoopValue]='O';
    }

}
//END OF FILL GRID//
printGrid(grid); // Note the change here
Scanner sc =new Scanner(System.in);
System.out.println("Please Choose the Co-ordinates of your first ship");
System.out.println("X = ");
int x = sc.nextInt();
System.out.println("Y = ");
int y = sc.nextInt(); 

grid[x][y] = 'S';  
printGrid(grid); // Note the change here!

这是一个示例运行:

Players Board

O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  Please Choose the Co-ordinates of your first ship
X = 
3
Y = 
3

O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  S  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  
O  O  O  O  O  O  O  O  O  O  

完整代码如下:

public static void main(String[] args) {
    System.out.println ("Players Board");


    char [][] grid = new char [10][10];
    for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)
    {

        for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
        {
            grid[outerLoopValue][innerLoopValue]='O';
        }

    }
    printGrid(grid); // Note the change here
    Scanner sc =new Scanner(System.in);
    System.out.println("Please Choose the Co-ordinates of your first ship");
    System.out.println("X = ");
    int x = sc.nextInt();
    System.out.println("Y = ");
    int y = sc.nextInt();

    grid[x][y] = 'S';
    printGrid(grid); // Note the change here!
}

public static void printGrid(char[][] grid) {
    for(int outerLoopValue = 0; outerLoopValue<10;outerLoopValue++)
    {
        System.out.println("");
        for(int innerLoopValue = 0; innerLoopValue<10;innerLoopValue++)
        {
            System.out.print(grid[outerLoopValue][innerLoopValue]+"  ");
        }
    }
}