if-elif-else in Bash Scripting - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the if statement in bash scripting?

The if statement lets the script make decisions by running commands only if a condition is true.

beginner

How do you write an elif branch in bash scripting?

Use elif [ condition ]; then to check another condition if the first if was false.

beginner

What does the else block do in an if-elif-else structure?

The else block runs commands when all previous if and elif conditions are false.

intermediate

Write a simple bash if-elif-else structure to check if a number is positive, negative, or zero.

Example:

if [ "$num" -gt 0 ]; then
  echo "Positive"
elif [ "$num" -lt 0 ]; then
  echo "Negative"
else
  echo "Zero"
fi

beginner

Why do you need to use fi in bash scripts?

Because fi marks the end of an if block, telling the shell where the conditional ends.

In bash scripting, which keyword starts an alternative condition after if?

A elif

B else

C endif

D elseif

The elif keyword is used to check another condition if the first if condition is false.

What symbol ends an if block in bash?

A end

B done

C fi

D stop

In bash, fi is used to close an if block.

What happens if all if and elif conditions are false and there is no else block?

A The script restarts

B The script runs the last <code>elif</code> block

C The script throws an error

D No commands inside the <code>if</code> structure run

If no conditions are true and no else block exists, none of the commands inside the if structure run.

Which of these is the correct syntax for an if condition in bash?

A if (condition) { }

B if [ condition ]; then

C if condition then

D if { condition }

Bash uses square brackets and then keyword: if [ condition ]; then.

What does the else block do in an if-elif-else statement?

A Runs if all previous conditions are false

B Ends the script

C Runs only if <code>elif</code> is true

D Runs if the first <code>if</code> is true

The else block runs commands only if all previous if and elif conditions are false.

Explain how an if-elif-else structure works in bash scripting.

Think about how you decide between multiple choices in real life.

Write a bash script snippet using if-elif-else to check if a variable is equal to 'yes', 'no', or something else.

Use square brackets and remember to close with fi.