JavaScript Exercises: Create stacks from arrays

JavaScript Stack: Exercise-23 with Solution

Write a JavaScript program that can create stacks from arrays.

In this exercise, we create an array myArray containing the values [1, 2, 3, 4, 5]. We then create a new stack object 'stack' using the Stack constructor function. We then call the from_Array method on 'stack', passing in myArray as the argument. This creates a new stack with the same values as myArray. Finally, we use the displayStack method to display the ‘stack’ elements

Sample Solution:

JavaScript Code:

class Stack {
  constructor() {
    this.items = [];
  }
  push(element) {
    this.items.push(element);
  }
  pop() {
    if (this.items.length === 0) {
      return null;
    }
    return this.items.pop();
  }

  peek() {
    if (this.items.length === 0) {
      return null;
    }
    return this.items[this.items.length - 1];
  }
  size() {
    return this.items.length;
  }
  isEmpty() {
    return this.items.length === 0;
  }
  clear() {
    this.items = [];
  }
  toArray() {
    return this.items.slice(); // return a copy of the items array
  }
  fromArray(array) {
    this.items = array.slice(); // copy the array to the items array
  } 
  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();
 }        
}
const myArray = [1, 2, 3, 4, 5];
const stack = new Stack();
stack.fromArray(myArray);
console.log(stack.displayStack(stack));

Sample Output:

Stack elements are:
1 2 3 4 5

Flowchart:

Live Demo:

See the Pen javascript-stack-exercise-23 by w3resource (@w3resource) on CodePen.

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