栈

手写栈

规则

• 先进后出
• 能拿栈的深度
• 能读取最顶层元素
• 判断空/清空

const stack = new Stack();
stack.push(1);
stack.push(2);
console.log(stack.top); // 2
console.log(stack.length); // 2
console.log(stack.pop()); // 2
console.log(stack.length); // 1
console.log(stack.isEmpty()); // false
stack.clear();
console.log(stack.isEmpty()); // true

class Stack {
    stack = [];
    push(item) {
        this.stack.push(item);
    }
    pop(item) {
        return this.stack.pop(item);
    }
    get top() {
        return this.stack[this.stack.length -1];
    }
    get length() {
        return this.stack.length;
    }
    clear() {
        this.stack = [];
    }
    isEmpty() {
        return this.stack.length === 0;
    }
}