Conditional variable assignment/ substitution

Bash does support the conditional variable assignment/ substitution e.g.  below code snippet

#! /bin/bash

name=${2:-"Juned"}

if [ "$name" != "Juned" ];then

echo  "hello $name"

else

echo "bye"

fi

will define the variable name with second command line parameter , but if there is no second command line parameter then the name is defaulted to Juned