<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script type="text/javascript">
var client = function () {
var engine = {
//内核
ie: 0,
gecko: 0,
webkit: 0,
khtml:0,
opera:0,
//具体版本
ver: null
};
var browser = {
//浏览器
ie: 0,
firefox: 0,
safari: 0,
konq: 0,
opera: 0,
chrome: 0,
//具体的版本
ver: null
};
return {
engine: engine,
browser: browser
};
}();
var ua = navigator.userAgent;
if (window.opener) {
engine.ver =browser.ver = window.opera.version();
engine.opera = browser.opera = parseFloat(engine.ver);
}else if (/AppleWebKit\/(\S+)/.test(ua)) {
engine.ver = RegExp["$1"];
engine.webkit = parseFloat(engine.ver);
//确定是Chrome还是Safari
if (/Chrome\/(\S+)/.test(ua)) {
browser.ver = RegExp["$1"];
browser.chrome = parseFloat(browser.ver);
}else{
//近似地确定版本号
var safariVersion = 1;
if (engine.webkit < 100) {
safariVersion = 1;
}else if (engine.webkit < 312) {
safariVersion = 1.2;
}else if (engine.webkit < 412) {
safariVersion = 1.3;
}else {
safariVersion = 2;
}
browser.safari = browser.ver = safariVersion;
}
}else if (/KHTML\/(\S+)/.test(ua) || /Konqueror\/([^;]+)/.test(ua)) {
engine.ver = RegExp["$1"];
engine.khtml = browser.konq = parseFloat(engine.ver);
}else if (/rv:([^\)]+)\) Gecko\/\d{8}/.test(ua)) {
engine.ver = RegExp["$1"];
engine.khtml = browser.konq = parseFloat(browser.ver);
//确定是不是Firefox
if (/firefox\/(\S+)/.test(ua)) {
browser.ver = RegExp["$1"];
browser.firefox = parseFloat(browser.ver);
}
}else if (/MSIE ([^;]+)/.test(ua)) {
engine.ver = browser.ver = RegExp["$1"];
engine.ie = browser.ie = parseFloat(engine.ver);
}
if (client.engine.webkit){
if(client.browser.chrome){
alert("使用的浏览器是chrome")
}else if(client.browser.safari){
alert("浏览器是safari");
}else if (client.engine.gecko){
if (client.browser.firefox){
alert("浏览器是fir");
}else {
}
}
}
</script>
</head>
<body>
</body>
</html>
总是出现Uncaught ReferenceError: engine is not defined;
为什么变量保存了调用函数后的值 engine 仍然是未定义的?