Conditional validation in Laravel - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to require the 'email' field only if 'subscribe' is true.

Laravel

$request->validate([
    'email' => '[1]:subscribe,true'
]);

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

Arequired_if

Brequired

Cnullable

Dsometimes

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'required' makes the field always required.

Using 'nullable' allows empty values even when required.

Using 'sometimes' does not enforce requirement based on another field.

The required_if rule makes the field required only when another field has a given value.

2fill in blank

medium

Complete the code to require 'password' only when 'change_password' is present in the request.

Laravel

$request->validate([
    'password' => '[1]'
]);

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

Arequired_if:change_password,true

Bsometimes

Crequired_without:change_password

Drequired_with:change_password

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'required_if' expects a specific value, not just presence.

Using 'required_without' triggers when the other field is missing.

Using 'sometimes' does not enforce requirement.

The required_with rule requires the field only if another specified field is present.

3fill in blank

hard

Fix the error in the validation rule to require 'phone' only if 'contact_method' equals 'phone'.

Laravel

$request->validate([
    'phone' => 'required_if:[1]'
]);

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

Acontact_method=phone

Bcontact_method,phone

Ccontact_method==phone

Dcontact_method

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' or '==' instead of a comma.

Omitting the value after the field name.

Using only the field name without value.

The required_if rule syntax is required_if:otherfield,value. Commas separate the field and value.

4fill in blank

hard

Fill both blanks to require 'address' only when 'country' is 'US' and 'state' is present.

Laravel

$request->validate([
    'address' => '[1]:country,US|[2]:state'
]);

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

Arequired_if

Brequired_without

Crequired_with

Dnullable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'required_without' instead of 'required_with'.

Mixing up the order of rules.

Using 'nullable' which allows empty values.

required_if checks the value of 'country'. required_with requires 'address' if 'state' is present.

5fill in blank

hard

Fill all three blanks to require 'discount_code' only if 'user_type' is 'member', 'purchase_amount' is greater than 100, and 'promo' is present.

Laravel

$request->validate([
    'discount_code' => '[1]:user_type,member|[2]:purchase_amount,100|[3]:promo'
]);

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

Arequired_if

Bgt

Crequired_with

Drequired

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'required' alone makes the field always required.

Using 'required_without' instead of 'required_with'.

Using '=' instead of ',' in rule parameters.

required_if checks 'user_type'. gt checks if 'purchase_amount' is greater than 100. required_with requires the field if 'promo' is present.

Practice

1. What is the main purpose of conditional validation in Laravel?

easy

A. To apply validation rules only when certain conditions are met

B. To validate all fields regardless of user input

C. To disable validation completely

D. To validate fields only on the server side

Solution

1. Step 1: Understand conditional validation concept

   Conditional validation means rules run only if specific conditions are true.

2. Step 2: Compare options with concept

   Only To apply validation rules only when certain conditions are met describes applying rules based on conditions, matching the concept.

3. Final Answer:

   To apply validation rules only when certain conditions are met -> Option A

4. Quick Check:

   Conditional validation = apply rules conditionally [OK]

Hint: Think: validate only when needed, not always [OK]

Common Mistakes:

• Assuming validation always runs on all fields
• Confusing conditional validation with disabling validation
• Thinking it only applies on client side

2. Which of the following is the correct syntax to apply a conditional validation rule in Laravel's validator?

easy

A. 'email' => 'required_when:contact_method,email|email'

B. 'email' => 'required|if:contact_method,email|email'

C. 'email' => 'required_if:contact_method,email|email'

D. 'email' => 'required_if(contact_method,email)|email'

Solution

1. Step 1: Recall Laravel's conditional validation syntax

   Laravel uses 'required_if:field,value' format for conditional rules.

2. Step 2: Check each option

   'email' => 'required_if:contact_method,email|email' matches the correct syntax; others use invalid keywords or formats.

3. Final Answer:

   'email' => 'required_if:contact_method,email|email' -> Option C

4. Quick Check:

   required_if syntax = correct [OK]

Hint: Remember: 'required_if:field,value' is Laravel's syntax [OK]

Common Mistakes:

• Using 'if' or 'required_when' which are invalid
• Using parentheses instead of colon in rule
• Mixing up rule order or separators

3. Given this validation rule in Laravel:

'phone' => 'required_if:contact_method,phone|digits:10'

What happens if contact_method is set to email and phone is empty?

medium

A. Validation fails because phone must be 10 digits

B. Validation passes but phone must be digits

C. Validation fails because phone is always required

D. Validation passes because phone is not required

Solution

1. Step 1: Understand 'required_if' behavior

   The 'phone' field is required only if 'contact_method' equals 'phone'.

2. Step 2: Apply condition with given input

   Since 'contact_method' is 'email', 'phone' is not required, so empty is allowed.

3. Final Answer:

   Validation passes because phone is not required -> Option D

4. Quick Check:

   required_if condition false = no requirement [OK]

Hint: If condition false, required_if skips validation [OK]

Common Mistakes:

• Assuming phone is always required
• Ignoring the condition in required_if
• Confusing digits rule as always mandatory

4. You wrote this validation rule:

'age' => 'required_if:status,active|integer|min:18'

But it always fails even when status is inactive. What is the likely problem?

medium

A. The 'min:18' rule is applied even when 'age' is not required, causing failure

B. The 'required_if' rule is case sensitive and should be 'Required_If'

C. The 'required_if' rule applies only when status is 'active', so failure means another issue

D. The pipe character '|' is missing between rules

Solution

1. Step 1: Analyze rule application order

   All rules run if field is present; 'min:18' runs even if 'age' is empty but present.

2. Step 2: Understand why validation fails when status is 'inactive'

   Since 'age' is not required, but if present and empty, 'min:18' fails because empty is invalid.

3. Final Answer:

   The 'min:18' rule is applied even when 'age' is not required, causing failure -> Option A

4. Quick Check:

   min rule runs if field present, causing failure [OK]

Hint: Use 'nullable' to allow empty when not required [OK]

Common Mistakes:

• Thinking 'required_if' is case sensitive
• Ignoring that min rule runs on empty values
• Assuming pipe character is missing

5. You want to validate a form where the password field is required only if the user_type is 'admin'. Also, if password is present, it must be at least 8 characters. Which validation rule set correctly implements this?

hard

A. 'password' => ['nullable', 'min:8']

B. 'password' => ['required_if:user_type,admin', 'string', 'min:8']

C. 'password' => ['required_if:user_type,admin', 'min:8']

D. 'password' => ['required_if:user_type,admin', 'nullable', 'min:8']

Solution

1. Step 1: Identify requirement for password field

   Password is required only if user_type is 'admin', so 'required_if:user_type,admin' is needed.

2. Step 2: Ensure password length validation applies only if present

   Adding 'string' and 'min:8' ensures password is string and minimum length 8 when present.

3. Step 3: Check options for correct combination

   'password' => ['required_if:user_type,admin', 'string', 'min:8'] correctly combines required_if, string, and min:8 without nullable, so password is required conditionally and validated properly.

4. Final Answer:

   'password' => ['required_if:user_type,admin', 'string', 'min:8'] -> Option B

5. Quick Check:

   required_if + min length = 'password' => ['required_if:user_type,admin', 'string', 'min:8'] [OK]

Hint: Use required_if plus min rule without nullable for conditional required [OK]

Common Mistakes:

• Adding 'nullable' disables required_if effect
• Omitting 'string' can cause unexpected validation
• Using min without required_if causes always required