for loop with range ({1..10}) in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of a simple for loop with brace expansion

What is the output of this Bash script?

for i in {1..5}; do echo $i; done

Bash Scripting

for i in {1..5}; do echo $i; done

A

1
2
3
4
5

B

0
1
2
3
4
5

C

1
2
3
4

D 1 2 3 4 5

💡 Hint

Brace expansion generates a sequence of numbers separated by spaces.

The brace expansion {1..5} generates numbers 1 to 5. The loop echoes each number on its own line.

💻 Command Output

intermediate

Behavior of for loop with variable expansion inside range

What will this script output?

start=3
end=7
for i in {$start..$end}; do echo $i; done

Bash Scripting

start=3
end=7
for i in {$start..$end}; do echo $i; done

A

3
4
5
6
7

B {3..7}

C 3 4 5 6 7

D Syntax error

💡 Hint

Brace expansion happens before variable expansion in Bash.

Brace expansion occurs before variable expansion, so {$start..$end} is not expanded as a numeric range; it becomes the literal string '{3..7}' after variable expansion.

📝 Syntax

advanced

Correct syntax for a for loop counting down with brace expansion

Which option correctly counts down from 10 to 1 using brace expansion in Bash?

A for i in {1..10..-1}; do echo $i; done

B for i in {10..1}; do echo $i; done

C for i in {10..1..1}; do echo $i; done

D for i in {10..1..-1}; do echo $i; done

💡 Hint

Brace expansion supports a step value for counting down.

The syntax {start..end..step} allows counting down with a negative step. {10..1..-1} counts from 10 down to 1.

🚀 Application

advanced

Using a for loop with brace expansion to create files

You want to create 5 empty files named file1.txt to file5.txt using a Bash for loop with brace expansion. Which command will do this?

A for i in {1..5}; do echo file$i.txt; done

B touch file{1..5}.txt

C for i in {1..5}; do touch file$i.txt; done

D for i in {1..5}; touch file$i.txt

💡 Hint

Use a loop to run the touch command multiple times with different file names.

Option C loops from 1 to 5 and creates each file with touch. Option C expands to 'touch file1.txt file2.txt file3.txt file4.txt file5.txt' creating all files without a loop; the task requires a for loop.

🔧 Debug

expert

Why does this for loop not print numbers 1 to 10?

Consider this script:

for i in {1..10} do
echo $i
done

Why does it fail to print numbers 1 to 10?

Bash Scripting

for i in {1..10} do
echo $i
done

A Missing semicolon or newline after {1..10} causes syntax error

B Variable $i is not defined before the loop

C Brace expansion does not work with for loops

D The loop variable must be declared with 'declare' before use

💡 Hint

Check the syntax of the for loop header carefully.

In Bash, the for loop header must end with a semicolon or newline before 'do'. Missing this causes a syntax error.