How can you echo a variable name made of variable names I.e $$var1$var2

In this test I'm expecting it to print "var1 is 999". user@penguin:~$ for num in {1..3}; do export var$num=9999 ; echo var$num is $var$num ; done var1 is 1 var2 is 2 var3 is 3 user@penguin:~$ echo $var1 $var2 $var3 9999 9999 9999 This prints the PID instead of the variabled named by the two variable names. user@penguin:~$ for num in {1..3}; do export var$num=9999 ; echo var$num is $$var$num ; done var1 is 316var1 var2 is 316var2 var3 is 316var3