I have a project with laravel 5.4 when i am installing xampp with php 7 or higher some function don't work.but when i installed xampp with 5.6.* all functionalty works fine specially ajax and json.
why its happen?
Another problem is In live server my server php version is 5.6 but in my phpmyadmin php version shows 7.2.
what's the problem?
I think you have multiple PHP versions installed on your live server. (you can check in your vhost configs)
PHP 7 has removed / deprecated some functions that are used in php 5.6 so yeah, you can get errors with PHP > 7.0 on older laravel versions, and errors on PHP < 7 with new Laravel versions.