Variable assignment (no spaces around =) in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to assign the value 'hello' to the variable greeting.

Bash Scripting

greeting[1]"hello"

Drag options to blanks, or click blank then click option'

A:=

B=

C==

D<-

Attempts:

3 left

💡 Hint

Common Mistakes

Adding spaces around the equals sign causes syntax errors.

Using double equals (==) instead of a single equals.

In bash scripting, variable assignment must have no spaces around the equals sign (=).

2fill in blank

medium

Complete the code to assign the output of the date command to the variable today.

Bash Scripting

today[1]$(date)

Drag options to blanks, or click blank then click option'

A=

B==

C:=

D->

Attempts:

3 left

💡 Hint

Common Mistakes

Adding spaces around the equals sign.

Using == instead of = for assignment.

Variable assignment in bash requires no spaces around the equals sign (=), even when assigning command output.

3fill in blank

hard

Fix the error in the variable assignment to set count to 5.

Bash Scripting

count[1]5

Drag options to blanks, or click blank then click option'

A<-

B==

C:=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using spaces around the equals sign.

Using double equals (==) which is for comparison, not assignment.

In bash, variable assignment must use a single equals sign with no spaces around it.

4fill in blank

hard

Fill both blanks to assign the string 'world' to the variable name without spaces around the equals sign.

Bash Scripting

name[1][2]"world"

Drag options to blanks, or click blank then click option'

A=

B==

C"

D'

Attempts:

3 left

💡 Hint

Common Mistakes

Adding spaces around the equals sign.

Using single quotes instead of double quotes (both work but double quotes are common).

Use '=' with no spaces for assignment and quotes around the string value.

5fill in blank

hard

Fill all three blanks to assign the output of the command 'whoami' to the variable user with no spaces around the equals sign.

Bash Scripting

user[1]$([2][3])

Drag options to blanks, or click blank then click option'

A=

Bwhoami

C(nothing)

Dwho am i

Attempts:

3 left

💡 Hint

Common Mistakes

Adding spaces around the equals sign.

Using incorrect command names or extra spaces inside $().

Assign command output with no spaces around =, use $(command) syntax without extra spaces inside.

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