How to get file extension from a file name in ?

如何从的文件名获取文件扩展名？

For examples,

举些例子，

For “file.txt”, I want to get “txt”.

对于“ file.txt”，我想获取“ txt”。

This JavaScript function works well for me.

这个JavaScript函数对我来说效果很好。

function getExt(filename){    var idx = filename.lastIndexOf('.');    // handle cases like, ., filename    return (idx < 1) ? "" : filename.substr(idx + 1);}

It handles situations that the filename has no extensions like “.htaccess” and “filename”.

它可以处理文件名没有扩展名（如“ .htaccess”和“ filename”）的情况。

//This is fine if you know that there will be a nothing but a file name in "fileName" function getExt(fileName){     return (fileName.lastIndexOf('.') < 1) ?   null : fileName.('.').slice(-1);}//this is better for unexpected path data like: "/weird.folder/somefolder"function getExt(path){    return (path.match(/(?:.+..+[^\/]+$)/ig) != null) ? path.split('.').slice(-1): 'null';}

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