如何拆分包含数字的驼峰式字符串

Question

I have camel cased strings like this:

"numberOf40"
"numberOf40hc"

How can I split it like this?

["number", "Of", "40"]
["number", "Of", "40hc"]

I am using humps to decamelize keys so I can only pass a split regex as option. I am looking for an answer that only uses split function.

My best attempts:

const a = "numberOf40hc"

a.split(/(?=[A-Z0-9])/)
// ["number", "Of", "4", "0hc"]

a.split(/(?=[A-Z])|[^0-9](?=[0-9])/)
// ["number", "O", "40hc"]

Also I don't understand why the f is omitted in my last attempt.

Answer 1

You don't get the f in you last attempt (?=[AZ])|[^0-9](?=[0-9]) as this part of the last pattern [^0-9] matches a single char other than a digit and will split on that char.

You could also match instead of split

 const regex = /[AZ]?[az]+|\d+[az]*/g; [ "numberOf40", "numberOf40hc" ].forEach(s => console.log(Array.from(s.matchAll(regex), m => m[0])));

Using split only, you could use lookarounds with a lookbehind which is gaining more browser support.

 const regex = /(?=[AZ])|(?<=[az])(?=\d)/g; [ "numberOf40", "numberOf40hc" ].forEach(s => console.log(s.split(regex)));

Answer 2

 const a = "numberOf40hc" let b = a.split(/(\d+[az]*|[AZ][az]*)/).filter(a => a); console.log(b);

The .filter(a => a) is necessary because split , returns both the left and right side of a matched delimter. Eg 'a.'.split('.') returns both the left (ie 'a' ) and right (ie '' ) side of '.' .

Per your update regarding the need for compatibility with humps , it seems humps supports customizing the handler:

const humps = require('humps');

let myObj = {numberOf40hc: 'value'};

let decamelizedObj = humps.decamelizeKeys(myObj, key =>
        key.split(/(\d+[a-z]*|[A-Z][a-z]*)/).filter(a => a).join('_'));

console.log(decamelizedObj);

Answer 3

Try this:

 const splitStr = (str='') => str.split(/([AZ][az]+)/).filter(e => e); console.log( splitStr("numberOf40") ); console.log( splitStr("numberOf40hc") );