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Zeus

Arrays

Zeus provides dynamic arrays that can grow and shrink at runtime. Arrays are first-class objects with built-in methods.

Creating Arrays

Create an array using the new keyword:

let numbers: i32[] = new i32[];
let floats: f64[] = new f64[];
let flags: boolean[] = new boolean[];

You can also specify an initial capacity:

let numbers: i32[] = new i32[100];  // Pre-allocate space for 100 elements

Adding Elements

Use push to add elements to the end:

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);
numbers.push(30);
// Array now contains: [10, 20, 30]

Accessing Elements

Using get

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);
numbers.push(30);


let first: i32 = numbers.get(0);   // 10
let second: i32 = numbers.get(1);  // 20
let third: i32 = numbers.get(2);   // 30

Using Bracket Notation

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);


let first: i32 = numbers[0];   // 10
let second: i32 = numbers[1];  // 20

Modifying Elements

Using set

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);


numbers.set(0, 100);  // Replace first element
// Array now contains: [100, 20]

Using Bracket Notation

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);


numbers[0] = 100;  // Replace first element
numbers[1] = 200;  // Replace second element
// Array now contains: [100, 200]

Removing Elements

Use pop to remove and return the last element:

let numbers: i32[] = new i32[];
numbers.push(10);
numbers.push(20);
numbers.push(30);


let last: i32 = numbers.pop();  // Returns 30
// Array now contains: [10, 20]

Array Methods

MethodDescription
push(value)Add element to end
pop()Remove and return last element
get(index)Get element at index
set(index, value)Set element at index

Multi-Dimensional Arrays

2D Arrays

let matrix: i32[][] = new i32[][];


// Add rows
matrix.push(new i32[]);
matrix.push(new i32[]);


// Add elements to rows
matrix.get(0).push(1);
matrix.get(0).push(2);
matrix.get(1).push(3);
matrix.get(1).push(4);


// Access elements
let value: i32 = matrix.get(0).get(1);  // 2
let value2: i32 = matrix[1][0];          // 3

3D Arrays

let cube: i32[][][] = new i32[][][];


cube.push(new i32[][]);
cube.get(0).push(new i32[]);
cube.get(0).get(0).push(42);


let value: i32 = cube[0][0][0];  // 42

Object Arrays

Arrays can hold objects:

class Point {
  public x: i32;
  public y: i32;


  constructor(x: i32, y: i32) {
    this.x = x;
    this.y = y;
  }


  public sum(): i32 {
    return this.x + this.y;
  }
}


function main(): i32 {
  let points: Point[] = new Point[];


  points.push(new Point(1, 2));
  points.push(new Point(3, 4));
  points.push(new Point(5, 6));


  let p: Point = points.get(1);
  return p.sum();  // Returns 7
}

Practical Example

Here’s a function that sums all elements in an array:

function sumArray(arr: i32[], length: i32): i32 {
  let sum: i32 = 0;
  let i: i32 = 0;


  while (i < length) {
    sum = sum + arr.get(i);
    i = i + 1;
  }


  return sum;
}


function main(): i32 {
  let numbers: i32[] = new i32[];
  numbers.push(10);
  numbers.push(20);
  numbers.push(30);
  numbers.push(40);


  return sumArray(numbers, 4);  // Returns 100
}

2D Array Example

Working with a matrix:

class Matrix {
  public data: i32[][];
  public rows: i32;
  public cols: i32;


  constructor(r: i32, c: i32) {
    this.rows = r;
    this.cols = c;
    this.data = new i32[][];


    let i: i32 = 0;
    while (i < r) {
      this.data.push(new i32[c]);
      i = i + 1;
    }
  }


  public setValue(row: i32, col: i32, value: i32): void {
    this.data[row][col] = value;
  }


  public getValue(row: i32, col: i32): i32 {
    return this.data[row][col];
  }
}


function main(): i32 {
  let m: Matrix = new Matrix(3, 3);
  m.setValue(0, 0, 1);
  m.setValue(1, 1, 5);
  m.setValue(2, 2, 9);


  return m.getValue(1, 1);  // Returns 5
}

Bounds Checking

Array access is bounds-checked at runtime. Accessing an invalid index returns a default value:

let arr: i32[] = new i32[];
arr.push(10);


let safe: i32 = arr.get(0);    // 10
let oob: i32 = arr.get(100);   // Returns 0 (default for i32)

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