How can i convert double[][] array to String[][] array?

Question

I work on it but i can't do that.This code has address output i want to convert to string array from double array. What is wrong with this code.

public static String[][] getStrings(double[][] a) {
    double[][] c = { {2.0, 3.1,3,7}, {1.5,5.8,9.6,1} };
    String[][] s2d = new String[c.length][c.length];
    for (int i = 0; i < s2d.length; i++) {
        for(int j=0; j<s2d[i].length;j++){
            s2d[i][j]=String.valueOf(c);
            System.out.println(s2d);
        }
    }
    return s2d;
}

This is the output that i have:

[[Ljava.lang.String;2a139a55
[[Ljava.lang.String;2a139a55
[[Ljava.lang.String;2a139a55
[[Ljava.lang.String;2a139a55
[[Ljava.lang.String;2a139a55

Answer 1

You have several problems in this code. Here is a solution, more intuitive than what you have and will releave you from headache.

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Explanation

Within your method, you create a new String array of arrays with as much arrays as contained in your double[][] parameter. As the sizes of each array can vary, we are not initializing it.

new String[a.length][];

Then, we loop over all the arrays of doubles, convert them to String using Arrays#toString() (we trim the "[" "]" that are the first and last character of the output of this method) and split it to have an array of Strings.

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Solution

public static String[][] getStrings(double[][] a) {
    String[][] output = new String[a.length][];
    int i = 0;
    for (double[] d : a){
        output[i++] = Arrays.toString(d).replace("[", "").replace("]", "").split(",");
    }
    return output;
}

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Input

public static void main(String[]a) {
    double[][] ds = { { 2.0, 3.1, 3, 7 }, { 1.5, 5.8, 9.6, 1 } };
    for (String[] s : getStrings(ds)){
        System.out.println(Arrays.toString(s));
    }
}

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Output

[2.0,  3.1,  3.0,  7.0]
[1.5,  5.8,  9.6,  1.0]