EN
JavaScript - get file extension
3 points
In this article, we would like to show you how to get a file extension in JavaScript.
Practical example:
xxxxxxxxxx1
const isSeparator = (value) => value === '/'|| value === '\\' || value === ':';2
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const getExtension = (path) => {4
for (let i = path.length - 1; i > -1; --i) {5
const value = path[i];6
if (value === '.') {7
if (i > 1) {8
if (isSeparator(path[i - 1])) {9
return '';10
}11
return path.substring(i + 1);12
}13
return '';14
}15
if (isSeparator(value)) {16
return '';17
}18
}19
return '';20
};21
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// Usage example:24
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// -- Common:26
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console.log(getExtension("image.png")); // png28
console.log(getExtension("audio.mp3")); // mp329
console.log(getExtension("document.pdf")); // pdf30
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console.log(getExtension(".")); //32
console.log(getExtension("..")); //33
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console.log(getExtension(".htaccess")); //35
console.log(getExtension(".tar.gz")); // gz36
console.log(getExtension("makefile")); //37
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// -- Unix/Linux/macOS:39
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console.log(getExtension("/path/.htaccess")); //41
console.log(getExtension("/path/.tar.gz")); // gz42
console.log(getExtension("/path/makefile")); //43
console.log(getExtension("/path/example.pdf")); // pdf44
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// -- Windows:46
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console.log(getExtension("C:\\path\\.htaccess")); //48
console.log(getExtension("C:\\path\\.tar.gz")); // gz49
console.log(getExtension("C:\\path\\makefile")); //50
console.log(getExtension("C:\\path\\example.pdf")); // pdf51
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// -- Also:53
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console.log(getExtension("C:.htaccess")); //55
console.log(getExtension("C:.tar.gz")); // gz56
console.log(getExtension("C:makefile")); //57
console.log(getExtension("C:example.pdf")); // pdf
