What's the purpose of this weird capitalize function?

I'm looking through the code for kibo.js and found this function:

开发者_开发百科

Kibo.capitalize = function(string) {
  return string.toLowerCase().replace(/^./, function(match) { return match.toUpperCase(); });
};

Anyone have any ideas why they might use this instead of just .toUpperCase?

PS - Kibo is found at https://github.com/marquete/kibo/blob/master/kibo.js

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It basically converts the entire string to lower case first, and then capitalizes just the first letter.

capitalize:

TEST => Test
test => Test
teST => Test

...as opposed to toUpperCase:

test => TEST
teST => TEST
Test => TEST

toLowerCase:

TeST => test
TEST => test
tesT => test

Some languages also have a titleize method which capitalizes the first letter of each word, as in a title/proper name:

mary poppins          => Mary Poppins
a lovely and talented => A Lovely and Talented Title
what a title!         => What a Title!
the meaning of life   => The Meaning of Life
hello, world!         => Hello, World!

Notice that it doesn't capitalize "and", "of", "the", etc. unless they are the first word in the string.

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toUpperCase converts all letters to upper case letters. This function, Kibo.capitalize, first converts all letters to lower case and then converts only the first letter (/^./) of the string to an upper case letter.

Kibo.capitalize('hello') // returns 'Hello'
'hello'.toUpperCase() // returns 'HELLO'

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The function, well, capitalizes the string, i.e. turning the first letter to upper case and the following letters — to lowercase.

console.log(Kibo.capitalize('alEx'));

/*
 * Outputs:
 * 'Alex'
 */

---

>>> capitalize("hi mom")
"Hi mom"
>>> capitalize("HI MOM")
"Hi mom"
>>> capitalize("Hi Mom")
"Hi mom"