英文:
get 2D array from text file
问题
以下是翻译好的部分：
public static void main(String[] a) throws FileNotFoundException {
File file = new File("district3.txt");
Scanner scan = new Scanner(file);
String b;
String[] c;
int r = 6;
double[][] arr = new double[r][];
while (scan.hasNextLine()) {
// 将数字以字符串形式读取
b = scan.nextLine();
// 拆分字符串
c = b.split(" ");
// 将拆分的字符串转换为 double 类型并存入二维数组
double[] row = new double[c.length];
for (int i = 0; i < c.length; i++) {
row[i] = Double.parseDouble(c[i]);
}
// 将当前行存入二维数组
arr[r - c.length] = row;
}
}
英文:
I'm trying to get the 2D array from the text file. So far I accessed the file and got all the numbers in the file, but all these numbers are string so I used split() and then convert it to double. How can convert this to double 2D array?
1.65 4.50 2.36 7.45 3.44 6.23
2.22 -3.24 -1.66 -5.48 3.46
4.23 2.29 5.29
2.76 3.76 4.29 5.48 3.43
3.38 3.65 3.76
2.46 3.34 2.38 8.26 5.34
This is what I have so far:
public static void main(String[] a) throws FileNotFoundException {
File file = new File("district3.txt");
Scanner scan = new Scanner(file);
String b;
String[] c;
int r = 6;
double[][]arr = new double[r][];
while(scan.hasNextLine()) {
//get number as String
b = scan.nextLine();
//split them
c = b.split(" ");
for(String i:c)
System.out.println(Double.parseDouble(i) );
}
}
答案1
得分: 2
将你的for循环内部的内容改为print，然后在你打印完所有数字后添加一个println：
for(String i:c)
System.out.print(i + " ");
System.out.println();
要存储数字，你可以按以下方式操作：
double[][] arr = new double[r][];
int i = 0;
while(scan.hasNextLine()) {
// 获取数字作为字符串
b = scan.nextLine();
// 拆分它们
c = b.split(" ");
arr[i] = new double[c.length];
for(int j = 0; j < c.length; ++j) {
arr[i][j] = Double.parseDouble(c[j]);
// 根据需要显示它们
System.out.print(c[j] + " ");
}
System.out.println();
++i;
}
英文:
Change your for to print inline and then add a println after you've printed all the numbers:
for(String i:c)
System.out.print(i + " ");
System.out.println()
To store the numbers you can do the following:
double[][]arr = new double[r][];
int i = 0;
while(scan.hasNextLine()) {
//get number as String
b = scan.nextLine();
//split them
c = b.split(" ");
arr[i] = new double[c.length];
for(int j = 0; j < c.length; ++j) {
arr[i][j] = Double.parseDouble(c[j]);
// Display them if needed
System.out.print(c[j] + " ");
}
System.out.println();
++i;
}
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