JS $符号

function $() { var elements = new Array(); for (var i = 0; i < arguments.length; i++) { var element = arguments[i]; if (typeof element == 'string') element = document.getElementById(element); if (arguments.length == 1) return element; elements.push(element); } return elements;}$("id")

 

这时$("id") 等价于 document.getElementById("id")