class Stack {
    private items: any[];
    constructor(){
        this.items = [];
    }
    push(...elements:any[]){
        this.items = this.items.concat(elements);
    }
    pop():any{
        return this.items.pop();
    }
    isEmpty():boolean{
        return this.items.length === 0;
    }
    clear(){
        this.items = [];
    }
    size():number{
        return this.items.length;
    }
    print():string{
        return this.items.toString();
    }
}

 class Queue{
    private items: any[];
    constructor(){
        this.items = [];
    }
    enqueue(...elements:any[]){
        this.items = this.items.concat(elements);
    }
    dequeue(): any{
        return this.items.shift();
    }
    front():any{
        return this.items[0];
    }
    clear(){
        this.items = [];
    }
    isEmpty():boolean{
        return this.items.length === 0;
    }
    size():number{
        return this.items.length;
    }
    print(){
        console.log(this.items.toString());
    }
}

var divDom = document.querySelector('div');
var computedStyle = window.getComputedStyle(divDom, null);
var width = computedStyle.width

// width/height + border + padding  + 滚动条
offsetWidth & offsetHeight

// margin + top
offsetLeft & offsetTop

// width/height + padding
clientWidth & clientHeight

// border + margin + top + 滚动条
clientLeft & clientTop

// width/height + padding
scrollWidth & scrollHeight

// 滚动位置
scrollLeft & scrollTop