String variables in Bash Scripting - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this Bash script?

Consider the following Bash script that manipulates string variables. What will it print?

Bash Scripting

name="Alice"
welcome="Hello, $name!"
echo "$welcome"

A Hello, !

B Hello, $name!

C Hello, Alice!

D name

💡 Hint

Remember how Bash replaces variables inside double quotes.

In Bash, variables inside double quotes are expanded to their values. So $name becomes Alice inside the string.

💻 Command Output

intermediate

What does this Bash script output when using single quotes?

Look at this script and decide what it prints:

Bash Scripting

name='Bob'
welcome='Hello, $name!'
echo "$welcome"

A Hello, !

B Hello, $name!

C Hello, Bob!

D name

💡 Hint

Single quotes prevent variable expansion in Bash.

Single quotes treat everything literally, so $name is not replaced by its value.

📝 Syntax

advanced

Which option correctly concatenates two strings in Bash?

You want to join two string variables, first="Good" and second="Morning". Which command correctly concatenates them into greeting?

Bash Scripting

first="Good"
second="Morning"

A greeting="$first$second"

B greeting=$first + $second

C greeting=$first.$second

D greeting="$first + $second"

💡 Hint

In Bash, string concatenation is done by placing variables side by side inside quotes.

Option A joins the two variables without spaces or operators, producing 'GoodMorning'.

🔧 Debug

advanced

Why does this Bash script produce an error?

This script tries to assign a string with spaces to a variable but fails. Identify the cause.

Bash Scripting

greeting=Hello World
echo "$greeting"

A Because the variable is read-only

B Because the variable name is invalid

C Because echo cannot print variables

D Because the string with spaces is not quoted

💡 Hint

Think about how Bash treats spaces in assignments.

Without quotes, Bash treats 'Hello' and 'World' as separate commands or arguments, causing an error.

🚀 Application

expert

What is the value of 'result' after running this script?

Given the script below, what is the value of the variable 'result'?

Bash Scripting

text="  Bash scripting  "
trimmed="${text##*( )}"
result="${trimmed%%*( )}"
echo "$result"

A Bash scripting

B gnitpircs hsaB

C scripting

D ash scripting

💡 Hint

Look up how parameter expansion with ## and %% works for trimming spaces.

The script uses Bash parameter expansion to trim leading and trailing spaces from the string.

Practice

1. What is the correct way to assign the string Hello to a variable named greeting in bash?

easy

A. greeting="Hello"

B. greeting = "Hello"

C. greeting: "Hello"

D. greeting <- "Hello"

Solution

1. Step 1: Understand bash variable assignment syntax

   In bash, variable assignment must have no spaces around the equals sign.

2. Step 2: Check the options for correct syntax

   greeting="Hello" uses no spaces and quotes the string correctly. The other options have invalid syntax.

3. Final Answer:

   greeting="Hello" -> Option A

4. Quick Check:

   No spaces around = and quotes needed [OK]

Hint: No spaces around = and use quotes for strings [OK]

Common Mistakes:

• Adding spaces around = causes syntax errors
• Forgetting quotes around strings with spaces
• Using wrong assignment symbols like : or <-

2. Which of the following correctly prints the value of the variable name in bash?

easy

A. echo name

B. echo $name

C. echo &name

D. echo %name

Solution

1. Step 1: Recall how to access variable values in bash

   Use the dollar sign ($) before the variable name to get its value.

2. Step 2: Evaluate each option

   echo $name uses $name correctly. echo name prints the literal word 'name'. The other options use invalid symbols.

3. Final Answer:

   echo $name -> Option B

4. Quick Check:

   Use $ to access variable value [OK]

Hint: Use $ before variable to print its value [OK]

Common Mistakes:

• Forgetting $ prints variable name, not value
• Using wrong symbols like & or %
• Confusing variable access with assignment

3. What will be the output of this bash script?

name="Alice"
echo "Hello, $name!"

medium

A. Hello, Alice!

B. Hello, $name!

C. Hello, name!

D. Hello, !

Solution

1. Step 1: Understand variable assignment and usage

   The variable name is assigned the string "Alice".

2. Step 2: Analyze the echo command with variable expansion

   The echo command uses double quotes, so $name is replaced by its value "Alice".

3. Final Answer:

   Hello, Alice! -> Option A

4. Quick Check:

   Variables expand inside double quotes [OK]

Hint: Variables expand inside double quotes, not single quotes [OK]

Common Mistakes:

• Expecting variable expansion inside single quotes
• Printing variable name literally without $
• Forgetting to assign variable before use

4. Identify the error in this bash script:

message = "Hi there"
echo $message

medium

A. Variable name is invalid

B. Quotes should be single quotes

C. Missing $ before variable in echo

D. Spaces around = cause syntax error

Solution

1. Step 1: Check variable assignment syntax

   In bash, no spaces are allowed around the equals sign when assigning variables.

2. Step 2: Analyze the given script

   The line message = "Hi there" has spaces around =, causing a syntax error.

3. Final Answer:

   Spaces around = cause syntax error -> Option D

4. Quick Check:

   No spaces around = in assignments [OK]

Hint: No spaces around = in variable assignment [OK]

Common Mistakes:

• Adding spaces around =
• Using wrong quotes type causes no error here
• Forgetting $ in echo prints variable name literally

5. You want to store a user's full name with spaces in a variable fullname and then print it. Which script correctly does this?

hard

A. fullname=John Doe
echo $fullname

B. fullname='John Doe'
echo fullname

C. fullname="John Doe"
echo $fullname

D. fullname=John_Doe
echo $fullname

Solution

1. Step 1: Assign string with spaces to variable

   Strings with spaces must be quoted to be assigned correctly in bash.

2. Step 2: Print the variable value

   Use echo $fullname to print the stored string value.

3. Final Answer:

   fullname="John Doe" echo $fullname -> Option C

4. Quick Check:

   Quote strings with spaces and use $ to print [OK]

Hint: Quote strings with spaces; use $ to print variable [OK]

Common Mistakes:

• Not quoting strings with spaces causes errors
• Printing variable name without $ prints literal text
• Using underscores instead of spaces changes the string