class Stack<T> {
private items: T[] = [];
// Push an element onto the stack
push(element: T): number {
return this.items.push(element);
}
// Pop an element from the stack
pop(): T | string {
if (this.isEmpty()) {
return "Stack is empty";
}
return this.items.pop() as T;
}
// Peek at the top element
peek(): T | string {
if (this.isEmpty()) {
return "Stack is empty";
}
return this.items[this.items.length - 1];
}
// Check if the stack is empty
isEmpty(): boolean {
return this.items.length === 0;
}
// Get the size of the stack
size(): number {
return this.items.length;
}
// Print all elements
print(): void {
for (const item of this.items) {
console.log(item);
}
}
// Clear the stack
clear(): void {
this.items = [];
}
// Optional: expose items safely (read-only)
getItems(): T[] {
return [...this.items];
}
}
const stack = new Stack<number>();
stack.push(12);
stack.push(17);
stack.push(18);
stack.push(19);
stack.push(20);
stack.push(21);
console.log(stack.pop()); // 21
console.log(stack.getItems()); // [12, 17, 18, 19, 20]
console.log(stack.peek()); // 20
console.log("size: " + stack.size());
console.log(stack.isEmpty()); // false
stack.pop(); // removes 20
stack.print(); // prints 12, 17, 18, 19
stack.clear();
console.log(stack.getItems()); // []
/*
run:
21
[12, 17, 18, 19, 20]
20
"size: 5"
false
12
17
18
19
[]
*/
