How to initialize multi-dimensional array in java

Question

I am new to java language. I don't know how initialize multi-dimeansional array. Please help?

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"}};

Answer 2

a multidimensional array can define an array of an array, the data that store in multidimensional is in tabular form like in a row form, the syntax of initialise the multidimensional array is :

data_type[1st dimension][2nd dimension][]..[Nth dimension] array_name = new data_type[size1][size2]….[sizeN];

where:

• data_type: Type of data to be stored in the array. For example int, char, etc.
• dimension: The dimension of the array created.
  For example: 1D, 2D, etc.
• array_name: Name of the array
• size1, size2, …, sizeN: Sizes of the dimensions respectively.