PHP string variable hump Method

? <PHP 

// Title requirements: Input format is "get-element-by-id " is an arbitrary character string, converts it to a string camelCasing, e.g. the getElementById / 
// example: $ str = "get-element- by-ID "; 

$ STR =" GET-Element-by-ID "; 
$ ARR = the explode ( '-', $ STR); 
for ($ I =. 1; $ I <COUNT ($ ARR); $ I ++) { 
    $ ARR [$ I] = ucfirst ($ ARR [$ I]); 
} 
$ = STR The implode ( '', $ ARR); 
echo $ STR; 

?>