Initialising a multidimensional array in Java

Question

What is the correct way to declare a multidimensional array and assign values to it?

This is what I have:

int x = 5;
int y = 5;

String[][] myStringArray = new String [x][y];

myStringArray[0][x] = "a string";
myStringArray[0][y] = "another string";

Answer 1

You can declare multi dimensional arrays like :

// 4 x 5 String arrays, all Strings are null
// [0] -> [null,null,null,null,null]
// [1] -> [null,null,null,null,null]
// [2] -> [null,null,null,null,null]
// [3] -> [null,null,null,null,null]

String[][] sa1 = new String[4][5];
for(int i = 0; i < sa1.length; i++) {           // sa1.length == 4
    for (int j = 0; j < sa1[i].length; j++) {     //sa1[i].length == 5
        sa1[i][j] = "new String value";
    }
}


// 5 x 0  All String arrays are null
// [null]
// [null]
// [null]
// [null]
// [null]
String[][] sa2 = new String[5][];
for(int i = 0; i < sa2.length; i++) {
    String[] anon = new String[ /* your number here */];
    // or String[] anon = new String[]{"I'm", "a", "new", "array"};
    sa2[i] = anon;
}

// [0] -> ["I'm","in","the", "0th", "array"]
// [1] -> ["I'm", "in", "another"]
String[][] sa3 = new String[][]{ {"I'm","in","the", "0th", "array"},{"I'm", "in", "another"}};