class Stack {
constructor() {
this.items = [];
}
push(element) {
this.items.push(element);
}
pop() {
if (this.isEmpty()) return "Underflow";
return this.items.pop();
}
peek() {
return this.items[this.items.length - 1];
}
isEmpty() {
return this.items.length === 0;
}
printStack() {
let stackString = "";
for (let i = 0; i < this.items.length; i++) {
stackString += this.items[i] + " ";
}
return stackString;
}
}
let stack = new Stack();
stack.push(10);
stack.push(20);
stack.push(30);
console.log(stack.printStack()); // Output: 10 20 30
stack.pop();
console.log(stack.printStack()); // Output: 10 20
A queue is a FIFO (First In, First Out) data structure. The first element added is the first one to be removed.