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Cover image for 1 line of code: How to camelCase a string
Martin Krause
Martin Krause

Posted on • Edited on

1 line of code: How to camelCase a string

#javascript #webdev #productivity #codequality 
const toCamelCase = str => str.replace(/[\._-\s]+(.)?/g, (_, m) => (m ? m.toUpperCase() : ""));
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Returns a new string in camel case.
Uses space, dot, underscore and dash as delimiter.

Optimised version 

const toCamelCase = str => str.replace(/[\s\._-]+\w/g, (m) => m[m.length-1].toUpperCase());
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The repository & npm package

You can find the all the utility functions from this series at github.com/martinkr/onelinecode
The library is also published to npm as @onelinecode for your convenience.

The code and the npm package will be updated every time I publish a new article.

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Top comments (6)

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xr0master profile image
Sergey Khomushin • • Edited

Let's benchmark.

const toCamelCase = str => str.replace(/[\s\._-]+\w/g, (m) => m[m.length-1].toUpperCase());
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Or make a part of the string: 'to camel case'.toCamelCase();

String.prototype.toCamelCase = function() {return this.replace(/[\s\._-]+\w/g, (m) => m[m.length-1].toUpperCase())}
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martinkr profile image
Martin Krause •

Benchmark
Half the time its the original, the other half the new version for me.

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xr0master profile image
Sergey Khomushin •

Thanks. In Chrome, my version is 25% faster. It was obvious, though. Grouping is a heavy operation.

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martinkr profile image
Martin Krause •

Thank you, I updated the article and the code.

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lexlohr profile image
Alex Lohr •

Perhaps only uppercase letters and use \w instead of ..

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martinkr profile image
Martin Krause •

Sure. You want to write the code for this and we're running it through the benchmarks?

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