Most efficient way of certain string manipulation in PHP?

Question

I have strings that need converting like so,

'hello world' = 'helloWorld'

And also the same in reverse,

'helloWorld' = 'hello world'

So far all I have for both the conversions is this for the first,

$str = 'hello world';
$str = lcfirst(str_replace(' ', '', ucwords($str))); // helloWorld

And the second,

$str = 'helloWorld';
$str = preg_split('/(?=[A-Z])/', $str);
$str = strtolower(implode(' ', $str)); // hello world

Can this not be achieved any easier or any more efficient?

The most efficient way is whichever is the most readable, without fail. Do not make your code an eye-sore for the sake of 0.04ms per request. — Amelia
– Amelia, Commented Jul 8, 2015 at 9:02

webbiedave · Accepted Answer · 2012-01-26 00:00:32Z

1

Your camelize code is already good. For the second, you could forgo the split and implode:

$str = 'helloWorld';
$str = strtolower(preg_replace('/(?<=\\w)([A-Z])/', ' \\1', $str));
echo $str;
// output: hello world

answered Jan 26, 2012 at 0:00

webbiedave

49k8 gold badges92 silver badges104 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Thanks will try this, I tried using preg_replace before but couldn't get it right.

This worked great! Could you tell me what ' \\1' that bit means please or a link so I could find out?

It's a back reference. It tells regex to take the text that it found in the original string and "paste" it back here.

Thank you this is better than what I was using.