C-style for loop in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of a C-style for loop counting down

What is the output of this Bash script using a C-style for loop?

Bash Scripting

for ((i=3; i>0; i--)); do echo -n "$i "; done

A 3 2 1 0

B 1 2 3

C 3 2 1

D 0 1 2 3

💡 Hint

Remember the loop starts at 3 and decreases until it is greater than 0.

The loop starts at 3 and decrements by 1 each time until i is no longer greater than 0. So it prints 3, 2, 1 with spaces.

💻 Command Output

intermediate

Sum of numbers using C-style for loop

What is the value of the variable 'sum' after running this script?

Bash Scripting

sum=0
for ((i=1; i<=5; i++)); do sum=$((sum + i)); done
echo $sum

A 15

B 10

C 5

D 0

💡 Hint

Add numbers from 1 to 5 inclusive.

The loop adds 1+2+3+4+5 which equals 15.

📝 Syntax

advanced

Identify the syntax error in this C-style for loop

Which option contains the correct syntax for a C-style for loop in Bash?

A for ((i=0; i<5; i++)); echo $i; done

B for ((i=0; i<5; i++)); do echo $i; done

C for (i=0; i<5; i++) do echo $i; done

D for ((i=0; i<5; i++)) do echo $i; done

💡 Hint

Check the placement of semicolons and parentheses.

Option B correctly uses double parentheses with semicolon before 'do'. Option B misses semicolon, B misses 'do' keyword, C uses wrong parentheses.

🔧 Debug

advanced

Why does this C-style for loop not print anything?

Given this script, why is there no output?

Bash Scripting

for ((i=5; i<5; i++)); do echo $i; done

A The loop condition i<5 is false at start, so loop never runs.

B The increment i++ is incorrect syntax.

C The loop variable i is not initialized.

D The echo command is missing.

💡 Hint

Check the loop condition and initial value.

Since i starts at 5 and the condition is i<5, it is false immediately, so the loop body never executes.

🚀 Application

expert

Create a C-style for loop to print even numbers from 2 to 10

Which option correctly prints even numbers 2 4 6 8 10 using a C-style for loop in Bash?

A for ((i=1; i<=10; i++)); do if (( i % 2 == 0 )); then echo -n "$i "; fi; done

B for ((i=2; i<10; i+=2)); do echo -n "$i "; done

C for ((i=2; i<=10; i++)); do echo -n "$i "; done

D for ((i=2; i<=10; i+=2)); do echo -n "$i "; done

💡 Hint

Use increment of 2 starting at 2 and include 10.

Option D uses i starting at 2, increments by 2, and includes 10, printing 2 4 6 8 10. Option D also prints correct numbers but uses an if condition inside the loop, which is valid but less direct. Option D stops before 10, missing 10. Option D prints all numbers 2 to 10.