if ($number4 == 1,2) {

##</code><code>##

print "Yes!\n" if ( 1 == 2, 3 );

##</code><code>##

if( grep { $number4 == $_ } 1, 2 ) {...

##</code><code>##

if( $number4 == 1 || $number4 == 2 ) { ...

##</code><code>##

use List::Util 'any';
# .........
if( any { $number4 == $_ } 1, 2 ) {...