What You'll Build

A dynamic form that makes fields required based on other field values. You'll create an account registration form where validation requirements change based on the selected account type.

What You'll Learn

How to make fields required based on dropdown selections
Using functions for dynamic validation requirements
Complex conditional logic with multiple dependencies
Creating intelligent forms that adapt validation rules

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Interactive Learning

Every code snippet below is fully editable! Feel free to modify the code, experiment with different values, and see your changes reflected instantly in the live preview on the right.

Use the play button to run different snippet, or the refresh button to restore the original example.

Tutorial Steps

Step 1: Starting Point

Let's start with an empty form function. This is where we'll build our conditional validation form step by step.

Step 2: Basic Fields

First, let's add the basic fields that will control our conditional validation. We'll create an account type dropdown and some basic fields.

💡 Tip:

Notice that the phone field is optional initially. We'll make it conditionally required based on the account type selection.

Step 3: Basic Conditional Required

Now let's make the phone field required only for business accounts. This demonstrates basic conditional validation.

💡 Tip:

The isRequired property can be a function that returns true/false. When it returns true, the field becomes required. Try selecting "Business" to see the phone field become required!

Step 4: Multiple Conditions

Let's add more fields with different conditional requirements. Company name is required for both business and enterprise accounts.

💡 Tip:

You can use logical operators like || (OR) to make fields required for multiple conditions. The employee count is only required for enterprise accounts.

Step 5: Complex Conditional Logic

Finally, let's add complex conditional logic that depends on multiple field values and conditions.

💡 Tip:

This example shows nested conditions - the website is only required for enterprise accounts that have a company name, and the description is only required for large enterprise companies (100+ employees).

Try It Yourself

Challenge 1: Add a field that's only required for personal accounts
Challenge 2: Create a field that's required when both account type is business AND phone is provided
Challenge 3: Add a field that's required for enterprise accounts with more than 500 employees

Next Steps

Excellent! You've learned how to create dynamic validation requirements. Ready to explore more advanced form validation patterns?

Continue to Dynamic Read-Only Fields Tutorial

Other learning paths:

Learn about custom validation messages
Master complex form validation logic
Create multi-step form validation