Function definition in Bash Scripting - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a function named greet.

Bash Scripting

function [1]() {
  echo "Hello!"
}

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

Agreet

Bhello

Csay_hello

Dwelcome

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different function name than asked.

Forgetting the parentheses after the function name.

The function name should be greet to match the task.

2fill in blank

medium

Complete the code to call the function named greet.

Bash Scripting

[1]

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

Afunction greet

Bcall greet

Crun greet

Dgreet()

Attempts:

3 left

💡 Hint

Common Mistakes

Writing 'call greet' which is not valid bash syntax.

Writing 'function greet' which defines a function, not calls it.

To call a function in bash, write its name followed by parentheses: greet().

3fill in blank

hard

Fix the error in the function definition to make it valid bash syntax.

Bash Scripting

function greet [1] {
  echo "Hi!"
}

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

A{}

B()

C[]

D<>

Attempts:

3 left

💡 Hint

Common Mistakes

Using curly braces or square brackets instead of parentheses.

Omitting parentheses entirely.

In bash, function parameters are declared with parentheses () after the function name.

4fill in blank

hard

Fill both blanks to define and call a function named say_hello.

Bash Scripting

function [1]() {
  echo "Hello, world!"
}

[2]()

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

Asay_hello

Bgreet

Chello

Dwelcome

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for definition and call.

Forgetting parentheses when calling the function.

The function name must be the same in definition and call: say_hello.

5fill in blank

hard

Fill all three blanks to define a function greet_user that takes a name and prints a greeting.

Bash Scripting

function [1]() {
  echo "Hello, $[2]!"
}

[3] "Alice"

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

Agreet_user

B1

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable name instead of argument position.

Calling the function with a different name.

Forgetting to use $ before the argument number.

The function name is greet_user. The first argument is accessed as $1. Call the function with greet_user "Alice".

Practice

1. What is the correct way to define a function named greet in bash?

easy

A. greet() { echo "Hello"; }

B. function greet[] { echo "Hello"; }

C. def greet() { echo "Hello"; }

D. function greet() echo "Hello"

Solution

1. Step 1: Understand bash function syntax

   Bash functions are defined using either name() { commands; } or function name { commands; }.

2. Step 2: Check each option

   greet() { echo "Hello"; } uses the correct syntax with parentheses and braces. Options B, C, and D have syntax errors or use wrong keywords.

3. Final Answer:

   greet() { echo "Hello"; } -> Option A

4. Quick Check:

   Function syntax = greet() { ... } [OK]

Hint: Use parentheses and braces to define bash functions [OK]

Common Mistakes:

• Using square brackets instead of parentheses
• Using Python 'def' keyword
• Omitting braces around commands

2. Which of the following is a valid function definition syntax in bash?

easy

A. function myFunc() { echo "Hi"; }

B. myFunc[] { echo "Hi"; }

C. function myFunc[] echo "Hi"

D. myFunc() echo "Hi"

Solution

1. Step 1: Recall valid bash function syntax

   Bash allows defining functions as function name() { commands; } or name() { commands; }.

2. Step 2: Evaluate options

   function myFunc() { echo "Hi"; } matches valid syntax. Options A and C use square brackets incorrectly. myFunc() echo "Hi" misses braces around commands.

3. Final Answer:

   function myFunc() { echo "Hi"; } -> Option A

4. Quick Check:

   Valid syntax includes 'function name() { ... }' [OK]

Hint: Remember to use braces {} to group commands in functions [OK]

Common Mistakes:

• Using square brackets instead of parentheses
• Omitting braces after function name
• Missing parentheses after function name

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

say_hello() {
  echo "Hello, $1!"
}
say_hello Alice

medium

A. Error: function not found

B. Hello, Alice!

C. say_hello Alice

D. Hello, $1!

Solution

1. Step 1: Understand function call with argument

   The function say_hello takes one argument and prints it using $1.

2. Step 2: Substitute argument and print

   Calling say_hello Alice replaces $1 with "Alice", so output is "Hello, Alice!".

3. Final Answer:

   Hello, Alice! -> Option B

4. Quick Check:

   Function argument $1 = Alice [OK]

Hint: Use $1 to access first argument inside bash functions [OK]

Common Mistakes:

• Printing literal $1 instead of its value
• Forgetting to call the function
• Syntax errors in function definition

4. Identify the error in this bash function definition:

function greet {
  echo "Hi"
}

medium

A. Missing parentheses after function name

B. Missing braces around commands

C. Missing semicolon after echo

D. No error; parentheses are optional with 'function' keyword

Solution

1. Step 1: Check function syntax with 'function' keyword

   Bash allows function name() { commands; } or function name { commands; }. Parentheses after the name are optional.

2. Step 2: Identify if there's an error

   The code function greet { echo "Hi"; } is valid syntax.

3. Final Answer:

   No error; parentheses are optional with 'function' keyword -> Option D

4. Quick Check:

   function name { ... } [OK]

Hint: Parentheses () are optional with 'function name' [OK]

Common Mistakes:

• Omitting parentheses after function name
• Confusing braces and parentheses
• Assuming semicolon needed after echo

5. You want to create a bash function sum that takes two numbers and prints their sum. Which function definition correctly does this?

hard

A. function sum { echo $1 + $2; }

B. sum() { echo $1 + $2; }

C. sum() { echo $(($1 + $2)); }

D. sum() { echo $1 $2; }

Solution

1. Step 1: Understand arithmetic in bash functions

   To add numbers, use arithmetic expansion $(()) inside echo.

2. Step 2: Evaluate each option

   sum() { echo $(($1 + $2)); } correctly sums $1 and $2 using $(($1 + $2)). Options A and B print strings with plus sign, not sum. sum() { echo $1 $2; } prints numbers without adding.

3. Final Answer:

   sum() { echo $(($1 + $2)); } -> Option C

4. Quick Check:

   Use $(()) for arithmetic in bash functions [OK]

Hint: Use $(()) to perform math inside bash functions [OK]

Common Mistakes:

• Printing variables without arithmetic expansion
• Omitting parentheses for function definition
• Using 'function' without parentheses