我正在尝试使用两种方法让我的程序写入文件。它编译没有错误，但是当打开它写入的文件时，只打印带有 (0,0) 的坐标。它应该从数组中打印 10000 个随机坐标。为什么它只打印出 (0,0) 坐标？另外，我是否将返回声明放在了正确的位置？
import java.io.*;
public class program
{
public static void main (String [] args) throws IOException
{
int points = 10000, dimension = 2, lengthA = 100;//int variables are declared and initialized
PrintWriter fileOut = new PrintWriter (new FileWriter ("arrayPoints.txt"));
double length [] = new double [dimension];//array for length is declared
double coordinate [][] = new double [points][dimension];//coordinate array is declared
for (int i = 0; i < points; i++){
fileOut.println(java.util.Arrays.toString(coordinate[i]));
}
fileOut.close();//writes to file
}//end main method
public static double writeTofile (double length[], double coordinate[][], int points, int dimension, int lengthA)
{
int x = 0, y = 0;
for(int z = 0; z < dimension; z++){//fills the length array with the the set value of lengthA
length[z] = lengthA;
}
for(x = 0; x < points; x++){//runs 1000 times to print 1000 data points
for (y = 0; y < dimension; y++){//runs 2 times to print an x and y coordinate
coordinate [x][y]= (2 *Math.random() - 1) * length[y];// finds a random number in the range and assiigns it to the coordinate array
}//end for
}//end for
return coordinate[x][y];
}//main method
}//program
我已经更改了我的代码并且它可以编译。但是，当您查看它打印到的文件时，会看到随机字母 ([D@76f1fad1[D@889ec59...)。为什么会这样？
import java.io.*;
public class program
{
public static void main (String [] args) throws IOException
{
int points = 10000, dimension = 2, lengthA = 100;//int variables are declared and initialized
PrintWriter fileOut = new PrintWriter (new FileWriter ("arrayPoints.txt"));
double length [] = new double [dimension];//array for length is declared
double coordinate [][] = new double [points][dimension];//coordinate array is declared
writeTofile(length, coordinate, points, dimension, lengthA);
for (int i = 0; i < points; i++){
fileOut.println(Arrays.toString(coordinate[i]));
}
fileOut.close();//writes to file
}//end main method
public static void writeTofile (double length[], double coordinate[][], int points, int dimension, int lengthA)
{
int x = 0, y = 0;
for(int z = 0; z < dimension; z++){//fills the length array with the the set value of lengthA
length[z] = lengthA;
}
for(x = 0; x < points; x++){//runs 1000 times to print 1000 data points
for (y = 0; y < dimension; y++){//runs 2 times to print an x and y coordinate
coordinate [x][y]= (2 *Math.random() - 1) * length[y];// finds a random number in the range and assiigns it to the coordinate array
}//end for
}//end for
}//main method
}//program
最佳答案
您没有调用用 main 方法中的值填充坐标数组的方法。
你可以这样调用它:
...
double coordinate [][] = new double [points][dimension];//coordinate array is declared
writeTofile(length, coordinate, points, dimension, lengthA)
for (int i = 0; i < points; i++){
...
至于 return 语句，它在正确的位置，但它会抛出 ArrayIndexOutOfBoundsException，因为它正在访问数组中不存在的偏移量。你想要一个返回值有什么用？
关于Java - 使用数组创建不同的方法，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/18969194/