Having trouble removing part of a string

Question

Given the string "123456789@test.com", I'm trying to remove from the '@' symbol on, I just want the numbers. I've been trying to split the string into an array and remove array elements based on if that element is numeric, then merging the elements back into a string. My code...

$employee_id = "123456789@test.com";
$employee_id_array = str_split($employee_id);

for($i = 0; $i < sizeof($employee_id_array); $i++) {
    if(is_numeric($employee_id_array[$i]) === false) {
        unset($employee_id_array[$i]);
        $employee_id_array = array_values($employee_id_array);
    }
}

$employee_id = implode($employee_id_array);

echo "employee id: $employee_id";

What it should print out: 123456789

What it actually prints out: 123456789ts.o

What am I missing?

Answer 1

echo strstr($employee_id, '@', true);

Answer 2

To get all the numbers in employee_id string:

$employee_id = "123456789@test.com";
preg_match_all('!\d+!', $employee_id, $matches);
echo $matches[0][0];

This will return all the numbers in the provided string.

If you want to get string before @ in employee_id then you can try this:

$employee_id = "123456789@test.com";
$output = explode('@', $employee_id);
echo $output[0];