FTP EnterPrize
Member
Posts : 1
Join date : 2011-07-05
 |  Subject: Can someone help me to understand this code? Sat Dec 10, 2011 4:23 am | |
| I have seen this code-piece different places - to use to make a webpage redirect if it is a mobilephone. I don't quit understand the code - especially the line: if (redirectagent.indexOf(redirect_devices[i]) != -1) - why -1 ? Please help me - I would be so thankful. - Code:
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<script language=javascript>
var redirectagent = navigator.userAgent.toLowerCase();
var redirect_devices = ['vnd.wap.xhtml+xml', 'sony', 'symbian', 'nokia', 'samsung', 'mobile', 'windows ce', 'epoc', 'nitro', 'j2me', 'midp-', 'cldc-', 'netfront', 'mot', 'up.browser', 'up.link', 'audiovox', 'blackberry', 'ericsson', 'panasonic', 'philips', 'sanyo', 'sharp', 'sie-', 'portalmmm', 'blazer', 'avantgo', 'danger', 'palm', 'series60', 'palmsource', 'smartphone', 'rover', 'au-mic', 'alcatel', 'ericy', 'vodafone', 'wap1', 'wap2', 'teleca',, 'lge', 'lg-', 'iphone', 'android', 'htc', 'dream', 'webos', 'bolt', ];
for (var i in redirect_devices) {
if (redirectagent.indexOf(redirect_devices[i]) != -1) {
location.replace("http://www.example.com");
}
}
</script>
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|
Speak
Member
Posts : 15
Join date : 2011-07-05
| | Subject: Re: Can someone help me to understand this code? Sat Dec 10, 2011 4:24 am | |
| The indexOf method returns -1 if the text you are searching for is *NOT* found.
So by saying != -1 that is really saying "if the given text is found anywhere in the string...".
It's kind of weird coding. If the useragent string contained, for example, "mot" at *ANY* place in the string (e.g., "Mosilla FireFox with remote scripting support") then it will count as "found". |
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Useless