Shell script parameters - a simpler way

#!/bin/sh

for param in "$@"; do
    eval "$param"
done

param1=${param1:-param1}
param2=${param2:-param2}
param3=${param3:-param3}

echo $param1 $param2 $param3

Usage:

param.sh param1=<param1> param2=<param2> param3=<param3>