javascript - Regex to split camel case

Question

I have a regular expression in JavaScript to split my camel case string at the upper-case letters using the following code (which I subsequently got from here):

"MyCamelCaseString"
    .replace(/([A-Z])/g, ' $1')
    .replace(/^./, function(str){ return str.toUpperCase(); })

Thus that returns:

"My Camel Case String"

Which is good. However, I want to step this up a notch. Could someone help me with a regex which will split if, and only if, the former character is lower-case and the latter is upper-case.

Thus, the above example will be the result I expect, but if I do:

"ExampleID"

Then I get returned:

"Example ID"

Instead of

"Example I D"

Since it's splitting at each upper-case and ignoring anything before it.

Hope that makes sense! And thanks :).

Answer 1

My guess is replacing /([A-Z])/ with /([a-z])([A-Z])/ and ' $1' with '$1 $2'

"MyCamelCaseString"
    .replace(/([a-z])([A-Z])/g, '$1 $2');

/([a-z0-9])([A-Z])/ for numbers counting as lowercase characters

console.log("MyCamelCaseStringID".replace(/([a-z0-9])([A-Z])/g, '$1 $2'))