JavaScript Exercises: Check if an element is present or not in a stack

JavaScript Stack: Exercise-8 with Solution

Check Element in Stack

Write a JavaScript program to implement a stack that checks if a given element is present or not in the stack.

Sample Solution:

JavaScript Code:

class Stack {
  constructor() {
    this.items = [];
  }

  push(element) {
    this.items.push(element);
  }

  pop() {
    if (this.isEmpty())
      return "Underflow";
    return this.items.pop();
  }

  peek() {
    if (this.isEmpty())
      return "No elements in Stack";
    return this.items[this.items.length - 1];
  }

  isEmpty() {
    return this.items.length === 0;
  }

 // Check whether a given element is present in the stack or not
  contains(element) {
    return this.items.includes(element);
  }
displayStack(stack) {
  console.log("Stack elements are:");
  let str = "";
  for (let i = 0; i < stack.items.length; i++)
    str += stack.items[i] + " ";
  return str.trim();
 }        
}

console.log("Initialize a stack:")
let stack = new Stack();
console.log("Input some elements on the stack:")
stack.push(1);
stack.push(4);
stack.push(3);
stack.push(2);
stack.push(5);
stack.push(6); 
console.log(stack.displayStack(stack));
let n = 10;
console.log("Check if "+n+ " is present in the said stack?");
console.log(stack.contains(n));  
n = 5;
console.log("Check if "+n+ " is present in the said stack?");
console.log(stack.contains(n));

Sample Output:

Initialize a stack:
Input some elements on the stack:
Stack elements are:
1 4 3 2 5 6
Check if 10 is present in the said stack?
false
Check if 5 is present in the said stack?
true

Flowchart:

Live Demo:

See the Pen javascript-stack-exercise-6 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

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