用于验证以+254开头的电话号码的正则表达式

i am trying to create a regex to match phone numbers starting with +254

examples of phone numbers +254716370730

+254856798768

+254765432135

i have tried

preg_match('/^\\+254\\d{9}/,$phonenumber');

but doesn't seem to work, any assistance will be highly appreciated

The correct syntax should be:

preg_match('/^\+254\d{9}/', $phonenumber);