Variable assignment (no spaces around =) 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. What will it print when run?

Bash Scripting

VAR=Hello
echo "$VAR"

A echo $VAR

B VAR=Hello

C Hello

D Syntax error

💡 Hint

Remember, in Bash, variable assignment must not have spaces around the equals sign.

The variable VAR is assigned the value Hello without spaces around =. Then echo prints the value of VAR, which is Hello.

💻 Command Output

intermediate

What error does this Bash script produce?

What happens when you run this script? MYVAR = World echo "$MYVAR"

Bash Scripting

MYVAR = World
echo "$MYVAR"

A bash: MYVAR: command not found

B MYVAR = World

C World

D Syntax error

💡 Hint

Check if spaces around = are allowed in Bash variable assignment.

Bash treats 'MYVAR' as a command because of the spaces around =, so it tries to run a command named MYVAR and fails.

📝 Syntax

advanced

Which option correctly assigns a variable in Bash?

Choose the correct way to assign the value '42' to the variable NUMBER in Bash.

A NUMBER = 42

B NUMBER =42

C NUMBER= 42

D NUMBER=42

💡 Hint

No spaces are allowed around the equals sign in Bash variable assignment.

Only option D has no spaces around =, which is the correct syntax for Bash variable assignment.

🚀 Application

advanced

What is the value of VAR after running this script?

Given this script, what is the value of VAR printed? VAR=foo VAR=bar VAR=baz echo "$VAR"

Bash Scripting

VAR=foo
VAR=bar
VAR=baz
echo "$VAR"

A foo

B baz

C bar

D Syntax error

💡 Hint

The last assignment to a variable overwrites previous ones.

The variable VAR is assigned three times. The last assignment sets it to 'baz', which is printed.

🔧 Debug

expert

Why does this Bash script fail to assign the variable correctly?

Examine the script below and identify why the variable assignment does not work as expected. MYVAR=Hello World echo "$MYVAR"

Bash Scripting

MYVAR=Hello World
echo "$MYVAR"

A The variable is assigned only 'Hello', and 'World' is treated as a command causing an error.

B The variable MYVAR is assigned the full string 'Hello World' correctly.

C The script prints 'Hello World' without errors.

D The variable assignment syntax is correct and works as intended.

💡 Hint

In Bash, spaces in variable assignment need special handling.

Without quotes, Bash treats 'World' as a separate command, causing an error. To assign a string with spaces, quotes are needed.

Practice

1. Which of the following is the correct way to assign the value hello to a variable named greet in bash?

easy

A. greet =hello

B. greet = hello

C. greet= hello

D. greet=hello

Solution

1. Step 1: Understand bash variable assignment rules

   Bash does not allow spaces around the = sign when assigning variables.

2. Step 2: Check each option for spaces

   Only greet=hello has no spaces around =. Options B, C, and D have spaces, which cause errors.

3. Final Answer:

   greet=hello -> Option D

4. Quick Check:

   No spaces around = means correct assignment [OK]

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

Common Mistakes:

• Adding spaces around = causes syntax errors
• Using quotes unnecessarily in simple assignments
• Trying to assign with spaces after =

2. Which of the following bash commands correctly assigns the value 42 to the variable num?

easy

A. num=42

B. num= 42

C. num =42

D. num = 42

Solution

1. Step 1: Identify spaces around the equal sign

   Bash requires no spaces around the = sign for variable assignment.

2. Step 2: Verify each option

   Only num=42 has no spaces around =. Others have spaces causing errors.

3. Final Answer:

   num=42 -> Option A

4. Quick Check:

   No spaces around = means correct syntax [OK]

Hint: Remember: no spaces around = in bash assignments [OK]

Common Mistakes:

• Leaving spaces around = causes syntax errors
• Confusing assignment with comparison operators
• Using quotes unnecessarily for numbers

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

name=John
echo $name

medium

A. name

B. Syntax error

C. John

D. $name

Solution

1. Step 1: Understand variable assignment and usage

   The variable name is assigned the value John without spaces around =.

2. Step 2: Understand echo with variable

   echo $name prints the value stored in name, which is John.

3. Final Answer:

   John -> Option C

4. Quick Check:

   Variable value printed, not variable name [OK]

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

Common Mistakes:

• Printing variable name instead of value
• Forgetting $ before variable in echo
• Adding spaces around = causing errors

4. Identify the error in the following bash script:

count =10
echo $count

medium

A. Spaces around = cause syntax error

B. Missing $ in echo

C. Variable name is invalid

D. No error, script runs fine

Solution

1. Step 1: Check variable assignment syntax

   The assignment count =10 has a space before =, which is not allowed in bash.

2. Step 2: Understand effect of spaces

   Spaces around = cause bash to treat count as a command, leading to syntax error.

3. Final Answer:

   Spaces around = cause syntax error -> Option A

4. Quick Check:

   No spaces around = means valid assignment [OK]

Hint: No spaces around = in assignment to avoid errors [OK]

Common Mistakes:

• Adding spaces around = in assignment
• Forgetting $ when printing variable
• Assuming variable names can have spaces

5. You want to store the current year in a variable year using the command date +%Y. Which of the following is the correct way to assign this output to year in bash?

hard

A. year = $(date +%Y)

B. year=$(date +%Y)

C. year= $(date +%Y)

D. year= '$(date +%Y)'

Solution

1. Step 1: Understand command substitution syntax

   To assign command output, use $(command) without spaces around =.

2. Step 2: Check each option for spaces and quotes

   year=$(date +%Y) has no spaces around = and uses correct command substitution syntax. Options A and C have spaces causing errors. year= '$(date +%Y)' uses quotes which are unnecessary and may cause literal assignment.

3. Final Answer:

   year=$(date +%Y) -> Option B

4. Quick Check:

   No spaces and correct command substitution [OK]

Hint: Use $(command) with no spaces around = for command output assignment [OK]

Common Mistakes:

• Adding spaces around = causes errors
• Using quotes around command substitution
• Forgetting to use $( ) for command output