Queue implementation

Queue.ts

class Node {
    public next: Node = null;

    constructor(
        public value: number
    ) {}
}

class Queue {
    private front: Node = null;
    private back: Node = null;
    private length: number = 0;

    public put(value: number): void {
        const node = new Node(value);

        this.length++;

        if (this.isEmpty()) {
            this.front = node;
            this.back = node;
            return;
        }

        this.back.next = node; // back = 1 -> 2 -> null
        this.back = node;
    }

    public get(): number {
        if(this.isEmpty()) {
            return null;
        }

        const value = this.front.value;

        this.front = this.front.next; // front = null | back = 2 -> null
        this.length--;

        if (this.isEmpty()) {
            this.back = null;
        }

        return value;
    }

    public size(): number {
        return this.length;
    }

    public isEmpty(): boolean {
        return this.front === null;
    }
}


const q = new Queue();


console.log('IS EMPTY:', q.isEmpty());
console.log('SIZE:', q.size());


q.put(1);
q.put(2);
q.put(3);


console.log('IS EMPTY:', q.isEmpty());
console.log('SIZE:', q.size());


console.log('GET:', q.get());
console.log('GET:', q.get());


console.log('IS EMPTY:', q.isEmpty());
console.log('SIZE:', q.size());


console.log('GET:', q.get());


console.log('IS EMPTY:', q.isEmpty());
console.log('SIZE:', q.size());


console.log(q);