Bash examples for my own memory's sake...

example.sh

#!/bin/bash

# check number of arguments, output a message to STDERR
if [[ "$#" -eq "0" ]]; then
  2>&1 echo "Usage: $0 FILE"
  exit 1
fi

# check if an argument equals a string
if [[ "$1" = "dev" ]]; then
  # ...
fi

# one line if...
if [[ "$1" = "dev" ]]; then echo "If"; else echo "Else"; fi

# arrays and looping over them
repos=(example1 example2)
for repo in "${repos[@]}"; do
  echo $repo
done