The solution I've done
Note :
at installing new version of xampp I got mysql errors
I think it because the version of mysql
so make sure that backup all databases before that
1- install xampp with php 5 from the site
2- install xampp with php 7 from the site
to here we must have php5.so and php7.so in same dir
3- open /opt/lampp/etc/extra/httpd-xampp.conf and add two line :
instead of one line of php 7
LoadModule php7_module modules/libphp7.so
LoadModule php5_module modules/libphp5.so
4- before running xampp file just comment the undesired version
to run php 5 :
#LoadModule php7_module modules/libphp7.so
LoadModule php5_module modules/libphp5.so
to run php 7 :
LoadModule php7_module modules/libphp7.so
#LoadModule php5_module modules/libphp5.so
5- start xampp