随着更高版本JavaScript的普及, 像[Array prototype新增了很多API](https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Objects/Array#Methods)都可以在大多数浏览器中直接使用.例如:
~~~
// give me a new array of all values multiplied by 10
[5, 6, 7, 8, 900].map(function (value) {
return value * 10;
});
// [50, 60, 70, 80, 9000]
// create links to specs and drop them into #links.
var linksList = document.querySelector('#links');
var links = [];
['html5', 'css3', 'webgl'].forEach(function (value) {
links.push(value.link('http://google.com/search?btnI=1&q=' + value + ' spec'));
});
linksList.innerHTML = links.join('');
// return a new array of all mathematical constants under 2
[3.14, 2.718, 1.618].filter(function (number) {
return number < 2;
});
// you can also use these extras on other collections link nodeLists
[].forEach.call(document.querySelectorAll('section[data-bucket]'),
function (elem, i) {
localStorage['bucket' + i] = elem.getAttribute('data-bucket');
});
~~~
通常情况下这些原生方法比手动编写循环要快:
~~~
for (var i = 0, len = arr.length; i < len; ++i) {
}
~~~
使用原生`JSON.parse()`比`json2.js`更加高效,安全.
原生的`String.prototype.trim`也是一个很好的例子, 这些功能不是HTML5中的,也应该得到广泛的应用.
