Data structures in Typescript

queue.ts

class Queue<T> {

    _size: number;
    _data = [] as T[];

    public constructor(size: number) {
        this._size = size;
    }

    public enqueue(element: T): void {
        if (this._data.length === this._size) {
            throw new Error('Queue overflow detected!');
        }
        this._data.push(element);
    }

    public dequeue(): void {
        this._data.shift();
    }

    public head(): T {
        return this._data[0];
    }
    
    public tail(): T {
        return this._data[this._data.length - 1];
    }
}

stack.ts

class Stack<T> {

    _size: number;
    _data = [] as T[];

    public constructor(size: number) {
        this._size = size;
    }

    public push(element: T): void {
        if (this._data.length === this._size) {
            throw new Error('Stack overflow detected!');
        }
        this._data.push(element);
    }

    public pop(): void {
        this._data.pop();
    }

    public bottom(): T {
        return this._data[0];
    }

    public top(): T {
        return this._data[this._data.length - 1];
    }
}