Add(argument_check.md) Add argument check solution (#323)

* Add(argument_check.md) Add argument check solution

* Change(argument_check.md) Add objectives of script

topics/shell/solutions/argument_check.md

@@ -0,0 +1,17 @@
+## Argument Check
+
+### Objectives
+
+Note: assume the script is executed with an argument
+
+1. Write a script that will check if a given argument is the string "pizza"
+2. If it's the string "pizza" print "with pineapple?"
+3. If it's not the string "pizza" print "I want pizza!"
+
+### Solution
+
+```
+#!/usr/bin/env bash
+
+[[ ${1} == "pizza" ]] && echo "with pineapple?" || echo "I want pizza!"
+```