Integer variables in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of integer arithmetic in Bash

What is the output of this Bash script?

Bash Scripting

a=5
b=3
c=$((a + b * 2))
echo $c

A 11

B 16

C 13

D 8

💡 Hint

Remember that multiplication has higher precedence than addition.

In Bash arithmetic, multiplication happens before addition. So b * 2 = 6, then a + 6 = 11.

📝 Syntax

intermediate

Correct integer assignment in Bash

Which option correctly assigns the integer value 10 to variable x in Bash?

A x=10

B x := 10

C x == 10

D let x = 10

💡 Hint

In Bash, assignment does not use spaces around = and no extra symbols.

Bash assigns variables with no spaces around =. 'x=10' is correct. 'let' is for arithmetic evaluation, not assignment. ':=' and '==' are invalid here.

🔧 Debug

advanced

Why does this Bash script fail to add integers?

Given this script: x=5 y=3 z=$x + $y echo $z What is the output and why?

Bash Scripting

x=5
y=3
z="$x + $y"
echo $z

A 53

B 8

C Syntax error

D 5 + 3

💡 Hint

Check how arithmetic is done in Bash and how variables are expanded.

The expression '$x + $y' is treated as a string, not arithmetic. So z becomes '5 + 3'. To do arithmetic, use $((x + y)).

🚀 Application

advanced

Calculate factorial using integer variables in Bash

Which script correctly calculates factorial of 4 and prints the result?

A

n=4
fact=1
while [ $n -gt 0 ]; do
  fact=$((fact * n))
  n=$((n - 1))
done
echo $fact

B

n=4
fact=1
for ((i=1; i<=n; i++)); do
  fact=$((fact * i))
done
echo $fact

C

n=4
fact=1
for i in $(seq 1 $n); do
  fact=$((fact + i))
done
echo $fact

D

n=4
fact=1
for i in {1..n}; do
  fact=$((fact * i))
done
echo $fact

💡 Hint

Check the loop syntax and arithmetic operation used for factorial.

Option B uses correct C-style for loop and multiplies fact by i each iteration. B fails because {1..n} does not expand n variable. A counts down but is correct factorial logic, but n is modified so loop ends correctly. D adds instead of multiplies.

🧠 Conceptual

expert

Integer variable behavior in Bash with arithmetic expansion

Consider this Bash snippet: x=10 y=3 z=$((x / y)) echo $z What is the output and why?

A 3.3333 because Bash supports floating point division

B 4 because Bash rounds up the division result

C 3 because Bash integer division truncates the decimal part

D Error because division is not supported in Bash arithmetic

💡 Hint

Bash arithmetic expansion works with integers only.

Bash integer arithmetic truncates results, so 10 / 3 equals 3, not 3.3333 or 4. Bash does not support floating point in $(( )).