condense.sh

#!/bin/bash
 
function readName {
    echo "Enter your full name:"
    read fullName
    clear
}
 
function cmprsName {
    comp=${ echo "$fullName" } | sed 's/ //g';
}
 
function sayItNow {
    echo $comp
}
 
function allTogether {
    readName
    cmprsName
    sayItNow
}
 
case $1 in
        -h | --help )           allTogether
                                exit
                                ;;
        * )                     echo "$0 -h"
                                exit 1
esac

1. Takes full name
2. Assigns to $fullName
3. $fullName passed to sed to remove spaces
4. Result assigned to $comp
5. Result echo to stdout

Changing 's/ //g' to 's/ /-/g' will add dashes instead of removing spaces