(4)http 模塊
回調 將后續函數作為參數放在起始函數中作為參數。
function learn(something) {
console.log(something);}
function we(callback,something) {
something += ' is cool';
callback(something);}
we(learn,'node.js');
we(function (something) {
console.log(something);},"jade");
同步／異步
I／O
