JavaScript中的获取DOM节点

var nodes = document.getElementsByTagName("input");
// 检测是不是数组
console.log(Array.isArray(nodes));     // false
console.log(Array.isArray([1,2,3]));     // true
console.log(nodes instanceof Array);     // false
console.log([1,2,3] instanceof Array);     // true
// 使用数组方法
console.log(nodes);     // (8) [input...]
nodes.pop();     // nodes.pop is not a function
console.log(nodes);

var div = document.getElementsByTagName("div");
var node = document.getElementById("div1");
 
            console.log(node.constructor);     // function HTMLDivElement() { [native code] }
            console.log(div.constructor);     // function HTMLCollection() { [native code] }
 
            console.log(node instanceof Node);     // true
            console.log(node instanceof Element);     // true
            console.log(node instanceof HTMLElement);     // true
            console.log(node instanceof HTMLDivElement);     // true 
            console.log(typeof node);     //object
 
            console.log(div instanceof HTMLCollection);     // true
            console.log(div instanceof NodeList);     // false
            console.log(div instanceof Node);     // false
            console.log(div instanceof Array);     // false
            console.log(typeof div);     // object