Available validation rules in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What does the 'required' validation rule do in Laravel?

In Laravel, what is the behavior of the 'required' validation rule when applied to a form input?

A It checks if the input is a valid email address.

B It allows the input field to be empty or missing without error.

C It ensures the input field must be present and not empty.

D It validates that the input is a numeric value.

💡 Hint

Think about whether the field can be left blank or missing.

The 'required' rule makes sure the input is present in the request and is not empty. If missing or empty, validation fails.

❓ component_behavior

intermediate

What output does this Laravel validation produce?

Given this validation rule in a Laravel controller:

$request->validate(['age' => 'integer|min:18']);

What happens if the input 'age' is '17'?

A Validation fails because age is less than 18.

B Validation passes because 17 is an integer.

C Validation passes because min rule is ignored for integers.

D Validation fails because age is not a string.

💡 Hint

Check what the 'min:18' rule means for integers.

The 'min:18' rule requires the integer to be at least 18. Since 17 is less, validation fails.

📝 Syntax

advanced

Which validation rule syntax is correct for checking a valid email in Laravel?

Select the correct syntax to validate that an input named 'email' is a valid email address in Laravel.

A 'email' => 'required|email'

B 'email' => 'email|required'

C 'email' => 'email|required|numeric'

D 'email' => 'required|email_address'

💡 Hint

Order matters for readability but not for correctness; check rule names carefully.

The correct rule names are 'required' and 'email'. 'email_address' is invalid and 'numeric' conflicts with email.

🔧 Debug

advanced

Why does this Laravel validation rule cause an error?

Consider this validation rule:

'username' => 'required|min:3|max'

Why will this cause a validation error?

A The 'min' rule must come after 'max'.

B The 'max' rule is missing a value and causes a syntax error.

C The 'required' rule cannot be combined with 'min' or 'max'.

D The 'username' field must be numeric for 'min' and 'max' to work.

💡 Hint

Check if all rules have required parameters.

The 'max' rule requires a value like 'max:10'. Without it, Laravel throws an error.

❓ state_output

expert

What is the validation result for this Laravel rule with input 'tags'?

Given this validation rule:

'tags' => 'array|min:2'

And the input:

tags = ['php']

What is the validation result?

A Validation passes because 'array' rule ignores 'min'.

B Validation passes because 'min:2' applies only to strings.

C Validation fails because 'tags' is not a string.

D Validation fails because the array has fewer than 2 items.

💡 Hint

Consider how 'min' works with arrays in Laravel validation.

The 'min:2' rule requires the array to have at least 2 items. Since 'tags' has only 1, validation fails.

Practice

1. Which Laravel validation rule ensures a field is not empty and must be present in the input data?

easy

A. required

B. nullable

C. sometimes

D. filled

Solution

1. Step 1: Understand the required rule

   The required rule means the field must be present and not empty in the input data.

2. Step 2: Compare with other rules

   nullable allows empty values, sometimes means the field is optional, and filled means if present, it cannot be empty.

3. Final Answer:

   required -> Option A

4. Quick Check:

   Field must be present and not empty = required [OK]

Hint: Remember: required means must be there and not empty [OK]

Common Mistakes:

• Confusing 'nullable' with 'required'
• Thinking 'sometimes' means required
• Using 'filled' expecting it to require presence

2. Which of the following is the correct syntax to validate that a field named email must be a valid email address in Laravel?

easy

A. 'email' => 'required|email_address'

B. 'email' => 'required|valid_email'

C. 'email' => 'required|mail'

D. 'email' => 'required|email'

Solution

1. Step 1: Identify the correct Laravel email validation rule

   Laravel uses email as the rule to check valid email format.

2. Step 2: Check syntax correctness

   The syntax uses pipe | to separate rules, so 'required|email' is correct.

3. Final Answer:

   'email' => 'required|email' -> Option D

4. Quick Check:

   Email validation rule is 'email' [OK]

Hint: Use 'email' rule for email validation, no extra words [OK]

Common Mistakes:

• Using 'email_address' instead of 'email'
• Using 'mail' or 'valid_email' which are invalid
• Forgetting to separate rules with pipe

3. Given the validation rule 'age' => 'required|integer|min:18', what happens if the input is age = 16?

medium

A. Validation passes because 16 is an integer

B. Validation passes because 'min' only applies to strings

C. Validation fails because 16 is less than the minimum 18

D. Validation fails because 16 is not required

Solution

1. Step 1: Understand the rules applied

   The rules require the field to be present, an integer, and at least 18.

2. Step 2: Check the input value against rules

   Input 16 is an integer and present, but less than 18, so it fails the min:18 rule.

3. Final Answer:

   Validation fails because 16 is less than the minimum 18 -> Option C

4. Quick Check:

   Integer less than min fails validation [OK]

Hint: min applies to numbers too, not just strings [OK]

Common Mistakes:

• Thinking min only applies to string length
• Ignoring the min rule when integer is less
• Assuming integer rule alone is enough

4. What is wrong with this validation rule? 'username' => 'required|min:3|max'

medium

A. The max rule is missing a value

B. The min rule should be min:3,5

C. The required rule cannot be combined with min

D. The pipe separator | is missing

Solution

1. Step 1: Analyze the max rule syntax

   The max rule requires a value like max:10 to specify the maximum length or number.

2. Step 2: Identify the error in the rule string

   Here, max is used without a value, which is invalid syntax.

3. Final Answer:

   The max rule is missing a value -> Option A

4. Quick Check:

   Rules like max need a value after colon [OK]

Hint: Rules like max and min always need a number after colon [OK]

Common Mistakes:

• Omitting the value after max or min
• Using commas inside min rule incorrectly
• Thinking required conflicts with min or max

5. You want to validate a password field that must be at least 8 characters and be confirmed by a matching password_confirmation field. Which validation rule set is correct?

hard

A. 'password' => 'required|string|min:8|regex:/[a-zA-Z]+[0-9]+/|confirmed'

B. 'password' => 'required|string|min:8|confirmed'

C. 'password' => 'required|min:8|alpha_num|confirmed'

D. 'password' => 'required|string|min:8|confirmed|same:password_confirmation'

Solution

1. Step 1: Understand the confirmed rule

   The confirmed rule automatically checks for a matching password_confirmation field.

2. Step 2: Check the rules for password complexity

   required|string|min:8 ensures presence, text type, and minimum length. The confirmed rule handles confirmation.

3. Step 3: Evaluate other options

   alpha_num restricts to letters and numbers but may exclude symbols; regex is complex and not required here; same is redundant with confirmed.

4. Final Answer:

   'password' => 'required|string|min:8|confirmed' -> Option B

5. Quick Check:

   Use confirmed for matching password fields [OK]

Hint: Use 'confirmed' to check matching confirmation field [OK]

Common Mistakes:

• Using 'same' instead of 'confirmed' for confirmation
• Overcomplicating with regex when not needed
• Forgetting to include 'required' or 'min:8'