Here are two PHP functions to convert strings between underscore format and camel case.
E.g. from firstName to first_name and vice versa.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | <?php /** * Translates a camel case string into a string with underscores (e.g. firstName -> first_name) * @param string $str String in camel case format * @return string $str Translated into underscore format */ function from_camel_case($str) { $str[0] = strtolower($str[0]); $func = create_function('$c', 'return "_" . strtolower($c[1]);'); return preg_replace_callback('/([A-Z])/', $func, $str); } /** * Translates a string with underscores into camel case (e.g. first_name -> firstName) * @param string $str String in underscore format * @param bool $capitalise_first_char If true, capitalise the first char in $str * @return string $str translated into camel caps */ function to_camel_case($str, $capitalise_first_char = false) { if($capitalise_first_char) { $str[0] = strtoupper($str[0]); } $func = create_function('$c', 'return strtoupper($c[1]);'); return preg_replace_callback('/_([a-z])/', $func, $str); } ?> |
Thought I might offer one way to do the latter w/out regexp.
Hi Joshua,
Thanks for that – I think it’s worth mentioning though that
lcfirstis only available on PHP >= 5.3 – so this may be useful:Paul
Well done, thanks – useful cleanly written functions. I like the lambda style functions, underused in PHP.
< ?PHP
//convert camelcase to normal string with spaces
//RadioProgramWhatChristiansShouldBe becomes
//Radio Program What Christians Should Be
function un_camelcase_string($str)
{
$newstr = '';
for($i = 0; $i 0 && ctype_upper($str{$i}))
{
$newstr .= ' '.$str{$i};
}
else
{
$newstr .= $str{$i};
}
}
$str = $newstr;
return $str;
}
?>
Other than the uh …. plug … in the string of the last example, it seems best: No doubt fastest, and probably more language/utf8 compatible.
// convertSomeString in convert_some_string
$string = preg_replace(‘~([A-Z])~’, ‘_$1′, $string);
$string = strtolower($string);
return trim($string, ” _”);
Thanks for the functions!
Just a word of caution to anyone using the create_function function: I was using it to translate database names to class property names 10,000+ times in a single script and started noticing I was having some memory leakage. Long story short, I found out that the functions created via create_function were never getting garbage collected and they were just hanging around taking up memory. Now I am just using
return preg_replace(“/\s+([a-z])/ie”, ’strtoupper(“$1″)’, trim($str));
for toCamelCase and Anton’s solution for fromCamelCase
Thanks for these great functions.
I modified them a bit to fit my needs. If someone might need a unicode version of them splitted into four functions (camelCase to undescore, PascalCase to underscore and reversed), feel free to visit my post about it:
http://www.webdevblog.info/php/convert-strings-between-camelcasepascalcase-and-underscored-notation/
What about this?
join(”, array_map(“ucwords”, explode(‘_’, $str_uscored)))
Anees, your solution is interesting, but prevents the use of lower camel case (which starts with lowercase).
Hi Paul,
create_function unfortunately leaks memory by default, because PHP never garbage collects create_function results.
So, call the two functions in a loop and see your memory grow and grow.
Below my current implementation:
public static function fromCamelCase($str)
{
$str[0] = strtolower($str[0]);
return preg_replace('/([A-Z])/e', "'_' . strtolower('\\1')", $str);
}
public static function toCamelCase($str, $capitaliseFirstChar = false)
{
if ($capitaliseFirstChar) {
$str[0] = strtoupper($str[0]);
}
return preg_replace('/_([a-z])/e', "strtoupper('\\1')", $str);
}
Works like a charm thanks for the tips
function toCamelCase($word) {
return lcfirst(str_replace(‘ ‘, ”, ucwords(strtr($word, ‘_-’, ‘ ‘))));
}
thanks a lot for these functions.