Last Updated: 2024-05-02

I could not get this variable $smsCounter to increment inside this PHP closure:

<?php

$smsCounter = 0;
Bus::assertDispatched(function (SendSms $job) use ($smsCounter) {
    $smsCounter = $smsCounter + 1;
    return true;
});
$this->assertEquals($smsCounter, 1);

The trick was to pass by reference instead. This enables the inner closure to modify the outer. Note the use of an ampersand (&) before the variable name below:

<?php
  Bus::assertDispatched(function (SendSms $job) use (&$smsCounter) {
    ...
  });
  ...