if-then-else in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of nested if-then-else in Bash

What is the output of this Bash script when run?

#!/bin/bash
x=5
if [ $x -gt 3 ]; then
  if [ $x -lt 10 ]; then
    echo "Between 4 and 9"
  else
    echo "10 or more"
  fi
else
  echo "3 or less"
fi

Bash Scripting

#!/bin/bash
x=5
if [ $x -gt 3 ]; then
  if [ $x -lt 10 ]; then
    echo "Between 4 and 9"
  else
    echo "10 or more"
  fi
else
  echo "3 or less"
fi

A Between 4 and 9

B 10 or more

C 3 or less

D Syntax error

💡 Hint

Check the conditions step by step and see which echo runs.

The variable x is 5, which is greater than 3 and less than 10, so the inner if condition is true and prints 'Between 4 and 9'.

📝 Syntax

intermediate

Identify the syntax error in this if-then-else script

Which option shows the correct way to fix the syntax error in this Bash script?

#!/bin/bash
x=10
if [ $x -eq 10 ]
  echo "x is 10"
else
  echo "x is not 10"
fi

Bash Scripting

#!/bin/bash
x=10
if [ $x -eq 10 ]
  echo "x is 10"
else
  echo "x is not 10"
fi

A Add 'then' after the if condition: if [ $x -eq 10 ]; then

B Add a semicolon after echo statement

C Replace 'fi' with 'end'

D Remove the else block

💡 Hint

Bash requires 'then' after the if condition.

The if statement must be followed by 'then' to be syntactically correct.

🔧 Debug

advanced

Why does this if-then-else script always print 'No'?

Consider this Bash script:

#!/bin/bash
var=""
if [ $var ]; then
  echo "Yes"
else
  echo "No"
fi

Why does it always print "No" even if var is empty?

Bash Scripting

#!/bin/bash
var=""
if [ $var ]; then
  echo "Yes"
else
  echo "No"
fi

A Because the script has a syntax error

B Because [ $var ] is false when var is empty, so else runs

C Because var is not defined

D Because echo is not inside the if block

💡 Hint

Check how Bash treats empty strings inside [ ]

In Bash, [ $var ] tests if $var is non-empty. If empty, condition is false and else runs.

🚀 Application

advanced

What is the output of this if-then-else with arithmetic test?

What does this Bash script print?

#!/bin/bash
num=7
if (( num % 2 == 0 )); then
  echo "Even"
else
  echo "Odd"
fi

Bash Scripting

#!/bin/bash
num=7
if (( num % 2 == 0 )); then
  echo "Even"
else
  echo "Odd"
fi

A Syntax error

B Even

C Odd

D No output

💡 Hint

Check if 7 is divisible by 2

7 modulo 2 is 1, so condition is false and else block prints 'Odd'.

🧠 Conceptual

expert

How many times does this loop print 'Hello'?

Analyze this Bash script:

#!/bin/bash
count=0
while [ $count -lt 3 ]; do
  if [ $count -eq 1 ]; then
    count=$((count + 2))
  else
    count=$((count + 1))
  fi
  echo "Hello"
done

How many times will "Hello" be printed?

Bash Scripting

#!/bin/bash
count=0
while [ $count -lt 3 ]; do
  if [ $count -eq 1 ]; then
    count=$((count + 2))
  else
    count=$((count + 1))
  fi
  echo "Hello"
done

A 4

B 3

C Infinite loop

D 2

💡 Hint

Trace the value of count each loop iteration.

Loop runs while count < 3. Iterations: count=0 -> print, count=1 -> print and add 2 (count=3), loop ends. So prints twice.