<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
What is the proper way to check if a variable of type String is empty in Bash?
<|im_end|>
<|im_start|>assistant
if [ -z "$var" ]; then 
    echo "The variable is empty."
fi<|im_end|>
