我需要在我的Transpose Java程序中使用double（）并同时使用扫描器

Question

我正在尝试编写一个程序，该程序首先接收转置大小（n X n）的输入，然后接受矩阵元素的输入，但是我需要元素为双精度而不是整数，并且我保持得到一个错误（我应该将double替换为int）。我该如何解决？我是一名新的Java学习者。提前谢谢这是我的代码：

import java.util.Scanner;
public class transpose_test {
    public static void main(String args[]) {
        int tra_size;
        Scanner sc=new Scanner(System.in);
        System.out.print("What size does the transpose have (n X n): ");
        tra_size=sc.nextInt();
        int a[][]=new int[tra_size][tra_size];
        System.out.println("Input the elements of matrix (a):");
        for(double i=0; i<tra_size; i++) {
            for(double j=0; j<tra_size; j++) {
                System.out.print("a [" + (i) + "],[" + (j) + "] = ");
                a[i][j] = sc.nextDouble(); // Keeps telling me to chanege the double into int
            }
        }
        System.out.println("Matrix a:");
        for(double i=0; i<tra_size; i++){
            for(double j=0; j<tra_size; j++){
                System.out.print(a[i][j] + "\t");
            }
            System.out.print("\n");
        }
        System.out.println("The Transpose Matrix is");
        for(double i=0; i<tra_size; i++){
            for(double j=0; j<tra_size; j++){
                System.out.print(a[j][i] + "\t");
            }
            System.out.print("\n");
        }
    }
}

Answer 1

对于for循环，您正在检查从0到矩阵大小。那应该是int。问题是您的2d数组类型。如果需要double数据类型的元素，则需要将该数组声明为double。

 double a [][]=new double [tra_size][tra_size]

尝试此代码。这样可以解决您的问题

    int tra_size;
    Scanner sc=new Scanner(System.in);
    System.out.print("What size does the transpose have (n X n): ");
    tra_size=sc.nextInt();
    double a [][]=new double [tra_size][tra_size];
    System.out.println("Input the elements of matrix (a):");
    for(int i=0; i<tra_size; i++) {
        for(int j=0; j<tra_size; j++) {
            System.out.print("a [" + (i) + "],[" + (j) + "] = ");
            a[i][j] = sc.nextDouble(); // Keeps telling me to chanege the double into int
        }
    }
    System.out.println("Matrix a:");
    for(int i=0; i<tra_size; i++){
        for(int j=0; j<tra_size; j++){
            System.out.print(a[i][j] + "\t");
        }
        System.out.print("\n");
    }
    System.out.println("The Transpose Matrix is");
    for(int i=0; i<tra_size; i++){
        for(int j=0; j<tra_size; j++){
            System.out.print(a[j][i] + "\t");
        }
        System.out.print("\n");
    }

Answer 2

我思考我看到了困惑，数组的indices >>不应为double（它们应为int）。数组a的元素应为double（double[][]而非int[][]）。喜欢，

Scanner sc = new Scanner(System.in);
System.out.print("What size does the transpose have (n X n): ");
int tra_size = sc.nextInt();
double[][] a = new double[tra_size][tra_size];
System.out.println("Input the elements of matrix (a):");
for (int i = 0; i < tra_size; i++) {
    for (int j = 0; j < tra_size; j++) {
        System.out.printf("a [%d],[%d] = ", i, j);
        a[i][j] = sc.nextDouble();
    }
}
System.out.println("Matrix a: ");
for (int i = 0; i < tra_size; i++) {
    for (int j = 0; j < tra_size; j++) {
        System.out.print(a[i][j] + "\t");
    }
    System.out.println();
}
System.out.println("The Transpose Matrix is");
for (int i = 0; i < tra_size; i++) {
    for (int j = 0; j < tra_size; j++) {
        System.out.print(a[j][i] + "\t");
    }
    System.out.println();
}

Answer 3

您需要明确两件事：