Array

• Arrays are sequential data structures consisting of values of the same type. T[] is an array of T.
• Arrays are mutable.
• Can access the individual elements of this array using the [i] notation. Array indexing starts with zero.
• The comparison operators - == or != : perform a deep comparison. The two arrays are equal if they have the same members in the same order.
• Unless the length is specified or inferred from the value, arrays are unbounded by length. That means they can grow up to any length based on the given index.

Sample

import ballerina/io;

public function main() {
    //Creates an int array by specifiying an array literal. 
    //Length is not speicfied, so this will create unbounded array
    int[] v = [1, 2, 3];
    io:println(v);
    io:println("Length of array v:", v.length());

    //Arrays can grow up to any length based on the given index. 
    v[9] = 10;
    io:println(v);
    io:println("Length of array v:", v.length());

    //Length is specified when creating,so  it can have only 3 elements maximum. 
    //If we try to store more than 3 elements it gives errors.
    int[3] v2 = [1,2,3];
    io:println(v2);

    //Access elements by index.
    io:println(v2[1]);

    //Multi dimensional array. 
    int[][] v3 = [[1, 2, 3], [10, 20, 30], [5, 6, 7]];
    io:println(v3);
    io:println(v3.length());

    //The `*` is used to infer the array size from array literal. 
    //Cannot assing more elements than the initial size. 
    int[*] v4 = [1, 2, 3, 4];
    io:println(v4.length());   
}

Output

[1,2,3]
Length of array v:3
[1,2,3,0,0,0,0,0,0,10]
Length of array v:10
[1,2,3]
2
[[1,2,3],[10,20,30],[5,6,7]]
3
4