在php中意外输出ltrim

Question

Can anybody explain this unusual output of ltrim

var_dump(ltrim('/btcapi/participation/set-user-event-participation','/btcapi'));

rticipation/set-user-event-participation //output

While expected output has

/participation/set-user-event-participation

Answer 1

Use str_replace if you are sure this is the only one occurence in your string.

$str = '/btcapi/participation/set-user-event-participation';
echo str_replace('/btcapi', $str); // returns: '/participation/set-user-event-participation'

Or regex if you need replace/remove just the first at the beginning of string.

$str = '/btcapi/participation/set-user-event-participation';
preg_replace ('~^/btcapi~', '', $str);