what causes memory limit php code example

Example 1: php memory_limit unlimited

//Unlimited momory limit
ini_set('memory_limit', '-1');

//Fixed memory limit
ini_set('memory_limit','2048M');

Example 2: Increase the PHP memory limit

/*
To increase the PHP memory limit setting, edit your PHP.ini file found under /usr/local/etc/php/7.4/.
Increase the default value (example: Maximum amount of memory a script may consume = 128MB) of the PHP memory limit line in php.ini.
*/

memory_limit = 256M