两个二维数组求和

Question

我试图获取两个2d数组输入，然后将它们添加在一起，但无法正确编译。出于某种原因，如果我在代码编译的方法之外声明"addedMatrix"，但addedMatrix是空的

以下是我目前所拥有的：

System.out.print("Enter Matrix 1 : ");
double[][] matrix1 = new double[3][3];
for (int r = 0; r < matrix1.length; r++)
{
for (int c = 0; c < matrix1[0].length; c++)
{
matrix1[r][c] = input.nextDouble();
}
}
System.out.print("Enter Matrix 2 : ");
double[][] matrix2 = new double[3][3];
for (int r = 0; r < matrix2.length; r++)
{
for (int c = 0; c < matrix2[0].length; c++)
{
matrix2[r][c] = input.nextDouble();
}
}
addMatrix(matrix1, matrix2);
System.out.println("The matrices added are : ");
for (int r = 0; r < addedMatrix.length; r++)
{
for (int c = 0; c < addedMatrix[0].length; c++)
{
System.out.print(addedMatrix[r][c]+ " ");
}
System.out.println();
}
public static double[][] addMatrix(double[][] arr1, double[][] arr2)
{
double[][] addedMatrix = new double[3][3];

for (int r = 0; r < addedMatrix.length; r++)
{
for (int c = 0; c < addedMatrix[0].length; c++)
{
addedMatrix[r][c] = arr1[r][c] + arr2[r][c];
}
}

return addedMatrix;
}

Answer 1

您的语法完全错误，首先需要一个主函数，然后还需要接受返回类型。

import java.util.Scanner;
public class Test {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter Matrix 1 : ");
double[][] matrix1 = new double[3][3];
for(int r = 0; r < matrix1.length; r++)
{
for(int c = 0; c < matrix1[0].length; c++)
{
matrix1[r][c] = input.nextDouble();
}
}
System.out.print("Enter Matrix 2 : ");
double[][] matrix2 = new double[3][3];
for(int r = 0; r < matrix2.length; r++)
{
for(int c = 0; c < matrix2[0].length; c++)
{
matrix2[r][c] = input.nextDouble();
}
}
double[][] addedMatrix = addMatrix(matrix1, matrix2);
System.out.println("The matrices added are : ");
for(int r = 0; r < addedMatrix.length; r++)
{
for(int c = 0; c < addedMatrix[0].length; c++)
{
System.out.print(addedMatrix[r][c]+ " ");
}
System.out.println();
}
}
public static double[][] addMatrix(double[][] arr1, double[][] arr2)
{
double[][] addedMatrix = new double[3][3];
for(int r = 0; r < addedMatrix.length; r++)
{
for(int c = 0; c < addedMatrix[0].length; c++)
{
addedMatrix[r][c] = arr1[r][c] + arr2[r][c];
}
}
return addedMatrix;
}
}