2.3. Arrays

Dynamic Growth

You can add elements to arrays dynamically by using the += operator. The array will be reallocated with sizes of powers of two:

int[] squares = {};
for (int i = 0; i < 100; i++) {
    squares += i * i;
}

No Boundary Checking

However, there is no runtime boundary checking for arrays in Vala:

int[] a = new int[10];
a[20] = 1;  // not safe!

(Optional boundary checking is planned for a future version of Vala.)

Multi-Dimensional Arrays

Java: jagged multi-dimensional arrays [][] (arrays of arrays)

int[][] matrix = new int[3][];
for (int[] row : matrix) {
    row = new int[4];
}

Vala: rectangular multi-dimensional arrays [,], [,,], etc. (allocated as one contiguous memory block), jagged array support planned

int[,] matrix = new int[3,4];

Illustration: rectangular vs. jagged multi-dimensional array (see original wiki for diagrams).