$string = explode( "-", $string );
$first = true;
foreach( $string as &$v ) {
if( $first ) {
$first = false;
continue;
}
$v = ucfirst( $v );
}
return implode( "", $string );

Untested code. Check the PHP docs for the functions im-/explode and ucfirst.

I would probably use preg_replace_callback(), like this:

function dashesToCamelCase($string, $capitalizeFirstCharacter = false) {
return preg_replace_callback("/-[a-zA-Z]/", 'removeDashAndCapitalize', $string);
}


function removeDashAndCapitalize($matches) {
return strtoupper($matches[0][1]);
}

No regex or callbacks necessary. Almost all the work can be done with ucwords:

function dashesToCamelCase($string, $capitalizeFirstCharacter = false)
{


$str = str_replace(' ', '', ucwords(str_replace('-', ' ', $string)));


if (!$capitalizeFirstCharacter) {
$str[0] = strtolower($str[0]);
}


return $str;
}


echo dashesToCamelCase('this-is-a-string');

If you're using PHP >= 5.3, you can use lcfirst instead of strtolower.

Update

A second parameter was added to ucwords in PHP 5.4.32/5.5.16 which means we don't need to first change the dashes to spaces (thanks to Lars Ebert and PeterM for pointing this out). Here is the updated code:

function dashesToCamelCase($string, $capitalizeFirstCharacter = false)
{


$str = str_replace('-', '', ucwords($string, '-'));


if (!$capitalizeFirstCharacter) {
$str = lcfirst($str);
}


return $str;
}


echo dashesToCamelCase('this-is-a-string');

Try this:

 return preg_replace("/\-(.)/e", "strtoupper('\\1')", $string);

This is simpler :

$string = preg_replace( '/-(.?)/e',"strtoupper('$1')", strtolower( $string ) );

this is my variation on how to deal with it. Here I have two functions, first one camelCase turns anything into a camelCase and it wont mess if variable already contains cameCase. Second uncamelCase turns camelCase into underscore (great feature when dealing with database keys).

function camelCase($str) {
$i = array("-","_");
$str = preg_replace('/([a-z])([A-Z])/', "\\1 \\2", $str);
$str = preg_replace('@[^a-zA-Z0-9\-_ ]+@', '', $str);
$str = str_replace($i, ' ', $str);
$str = str_replace(' ', '', ucwords(strtolower($str)));
$str = strtolower(substr($str,0,1)).substr($str,1);
return $str;
}
function uncamelCase($str) {
$str = preg_replace('/([a-z])([A-Z])/', "\\1_\\2", $str);
$str = strtolower($str);
return $str;
}

lets test both:

$camel = camelCase("James_LIKES-camelCase");
$uncamel = uncamelCase($camel);
echo $camel." ".$uncamel;

function camelCase($text) {
return array_reduce(
explode('-', strtolower($text)),
function ($carry, $value) {
$carry .= ucfirst($value);
return $carry;
},
'');
}

Obviously, if another delimiter than '-', e.g. '_', is to be matched too, then this won't work, then a preg_replace could convert all (consecutive) delimiters to '-' in $text first...

Alternatively, if you prefer not to deal with regex, and want to avoid explicit loops:

// $key = 'some-text', after transformation someText
$key = lcfirst(implode('', array_map(function ($key) {
return ucfirst($key);
}, explode('-', $key))));

You're looking for preg_replace_callback, you can use it like this :

$camelCase = preg_replace_callback('/-(.?)/', function($matches) {
return ucfirst($matches[1]);
}, $dashes);

This can be done very simply, by using ucwords which accepts delimiter as param:

function camelize($input, $separator = '_')
{
return str_replace($separator, '', ucwords($input, $separator));
}

NOTE: Need php at least 5.4.32, 5.5.16

One liner, PHP >= 5.3:

$camelCase = lcfirst(join(array_map('ucfirst', explode('-', $url))));

Another simple approach:

$nasty = [' ', '-', '"', "'"]; // array of nasty characted to be removed
$cameled = lcfirst(str_replace($nasty, '', ucwords($string)));

Overloaded one-liner, with doc block...

/**
* Convert underscore_strings to camelCase (medial capitals).
*
* @param {string} $str
*
* @return {string}
*/
function snakeToCamel ($str) {
// Remove underscores, capitalize words, squash, lowercase first.
return lcfirst(str_replace(' ', '', ucwords(str_replace('_', ' ', $str))));
}

here is very very easy solution in one line code

    $string='this-is-a-string' ;


echo   str_replace('-', '', ucwords($string, "-"));

output ThisIsAString

If you use Laravel framework, you can use just camel_case() method.

camel_case('this-is-a-string') // 'thisIsAString'

The TurboCommons library contains a general purpose formatCase() method inside the StringUtils class, which lets you convert a string to lots of common case formats, like CamelCase, UpperCamelCase, LowerCamelCase, snake_case, Title Case, and many more.

https://github.com/edertone/TurboCommons

To use it, import the phar file to your project and:

use org\turbocommons\src\main\php\utils\StringUtils;


echo StringUtils::formatCase('sNake_Case', StringUtils::FORMAT_CAMEL_CASE);


// will output 'sNakeCase'

Here's the link to the method source code:

https://github.com/edertone/TurboCommons/blob/b2e015cf89c8dbe372a5f5515e7d9763f45eba76/TurboCommons-Php/src/main/php/utils/StringUtils.php#L653

Here is another option:

private function camelcase($input, $separator = '-')
{
$array = explode($separator, $input);


$parts = array_map('ucwords', $array);


return implode('', $parts);
}

$stringWithDash = 'Pending-Seller-Confirmation'; $camelize = str_replace('-', '', ucwords($stringWithDash, '-')); echo $camelize; output: PendingSellerConfirmation

ucwords second(optional) parameter helps in identify a separator to camelize the string. str_replace is used to finalize the output by removing the separator.

function camelize($input, $separator = '_')
{
return lcfirst(str_replace($separator, '', ucwords($input, $separator)));
}


echo ($this->camelize('someWeir-d-string'));
// output: 'someWeirdString';

Try this:

$var='snake_case';
$ucword= ucword($var,'_');
echo $ucword;

Output:

Snake_Case

remove _ with str_replace

 str_replace('_','',$ucword); //SnakeCase

and result

 $result='SnakeCase';  //pascal case
echo lcfirst('SnakeCase');  //snakeCase (camel case)

the important thing is the approach here I used snake case and camel case in the example

In Laravel use Str::camel()

use Illuminate\Support\Str;


$converted = Str::camel('foo_bar');


// fooBar

Here is a small helper function using a functional array_reduce approach. Requires at least PHP 7.0

private function toCamelCase(string $stringToTransform, string $delimiter = '_'): string
{
return array_reduce(
explode($delimiter, $stringToTransform),
function ($carry, string $part): string {
return $carry === null ? $part: $carry . ucfirst($part);
}
);
}

Many good solutions above, and I can provide a different way that no one mention before. This example uses array. I use this method on my project Shieldon Firewall.

/**
* Covert string with dashes into camel-case string.
*
* @param string $string A string with dashes.
*
* @return string
*/
function getCamelCase(string $string = '')
{
$str = explode('-', $string);
$str = implode('', array_map(function($word) {
return ucwords($word);
}, $str));


return $str;
}

Test it:

echo getCamelCase('This-is-example');

Result:

ThisIsExample

private function dashesToCamelCase($string)
{
$explode = explode('-', $string);
$return = '';
foreach ($explode as $item) $return .= ucfirst($item);


return lcfirst($return);
}

Some very good solutions here. I compiled them together for easy c&p

declare(strict_types=1);
/**
* convert kebab-case to PascalCase
*/
function kebabToPascal( string $str ): string {
return str_replace( ' ', '', ucwords( str_replace( '-', ' ', $str ) ) );
}


/**
* convert snake_case to PascalCase
*/
function snakeToPascal( string $str ): string {
return str_replace (' ', '', ucwords( str_replace( '_', ' ', $str ) ) );
}


/**
* convert snake_case to camelCase
*/
function snakeToCamel( string $str ): string {
return lcfirst( snakeToPascal( $str ) );
}


/**
* convert kebab-case to camelCase
*/
function kebabToCamel( string $str): string {
return lcfirst( kebabToPascal( $str ) );
}






echo snakeToCamel( 'snake_case' ). '<br>';
echo kebabToCamel( 'kebab-case' ). '<br>';
echo snakeToPascal( 'snake_case' ). '<br>';
echo kebabToPascal( 'kebab-case' ). '<br>';


echo kebabToPascal( 'It will BREAK on things-like_this' ). '<br>';

In Yii2 you can use yii\helpers\Inflector::camelize():

use yii\helpers\Inflector;


echo Inflector::camelize("send_email");


// outputs: SendEmail

Yii provides a lot of similar functions, see the Yii2 Docs.

Try this ;)

$string = 'this-is-a-string';
$separator = '-';


$stringCamelize = str_replace(
$separator,
'',
lcfirst(
ucwords(
strtolower($string),
$separator
)
)
);


var_dump($stringCamelize); // -> 'thisIsAString'

This works for me:

function camelCase($string){
$chunks = preg_split("/\s+|-|_/",$string);


$camel = "";
        

foreach ($chunks as $idx => $chunk){
         

if ($idx===0){
$camel = strtolower($chunk);
}else{
$camel .= ucfirst($chunk);
}
}
return $camel;
}

The shortest and most elegant solution would be:

function dashesToCamelCase($string, $capitalizeFirstCharacter = false) {
$result = join("", array_map("ucfirst", explode("-", $string)));


if ($capitalizeFirstCharacter === false) {
return lcfirst($result);
}


return $result;
}