DSA using JavaScript

Input: &quot;stack implementation&quot; Output : &quot;implementation stack&quot;
Input: &quot;javascript is fun&quot; Output : &quot;fun is javascript&quot;

Stack

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

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

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

    peek() {
        if (this.isEmpty()) return null;
        return this.items[this.items.length - 1];
    }

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

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

    clear() {
        this.items = [];
    }
}

function reverseWords(sentence) {
    const stack = new Stack();
    const words = sentence.split(" ");
    let reversedSentence = "";

    // Push each word onto the stack
    for (let word of words) {
        stack.push(word);
    }

    // Pop each word to get them in reverse order
    while (!stack.isEmpty()) {
        reversedSentence += stack.pop() + " ";
    }

    return reversedSentence.trim();
}

// Sample Usage
console.log(reverseWords("hello world"));          // Output: "world hello"
console.log(reverseWords("stack implementation")); // Output: "implementation stack"
console.log(reverseWords("javascript is fun"));    // Output: "fun is javascript"