Question

How to implement queue in TypeScript

Answer 1

class Queue {
    private items:number[];

    constructor() {
        this.items = [];
    }
    
    enqueue(element: number) : number {
        return this.items.push(element);
    }
    
    dequeue() {
        if (this.items.length > 0) {
            return this.items.shift();
        } return -1

    }
    
    size() {
        return this.items.length;
    }

    
    peek() {
        return this.items[this.items.length - 1];
    }
    
    isEmpty() {
       return this.items.length == 0;
    }
   
    print() {
        let s:string = ""
        for (let i = 0; i < this.items.length; i++) {
          	s += this.items[i] + ", ";
      	}
        console.log(s);
    }
 
    delete(){
        this.items = [];
    }
}

let queue = new Queue();

queue.enqueue(5);
queue.enqueue(9);
queue.enqueue(2);
queue.enqueue(0);
queue.enqueue(5);
queue.enqueue(7);

queue.print();

queue.dequeue();
queue.print();

console.log(queue.peek());

console.log(queue.isEmpty());

console.log("size: " + queue.size());

queue.dequeue();
queue.print();

queue.delete();
queue.print();





/*
run:

"5, 9, 2, 0, 5, 7, " 
"9, 2, 0, 5, 7, " 
7 
false 
"size: 5" 
"2, 0, 5, 7, " 
"" 

*/

 

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