Check if a string can be used as a JavaScript variable name
Last updated 3 years ago by shinnn .
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$ cnpm install is-var-name 
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Check if a string can be used as a JavaScript variable name

isVarName('foo'); //=> true
isVarName('f o o'); //=> false


Use npm.

npm install is-var-name


import isVarName from 'is-var-name';


name: string
Return: boolean

It returns true if the string can be used as a valid JavaScript identifier name. If not, or the argument is not a string, it returns false.

isVarName('______________'); //=> true
isVarName('å'); //=> true

isVarName('123'); //=> false
isVarName('↑→↓←'); //=> false
isVarName('_;'); //=> false
isVarName(''); //=> false

isVarName(['foo']); //=> false
isVarName(); //=> false

Another solution

Instead of this module, you can use the regular expression that matches valid variable names.

Regular expression pros

is-var-name uses Function constructor but regular expression doesn't.

According to the ESLint documentation, new Function() is:

considered by many to be a bad practice due to the difficult in debugging and reading these types of functions.

Regular expression cons

Since the regular expression is too long (about 16,000 characters), it increases the file size of your library or application.


ISC License © 2018 Shinnosuke Watanabe

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