Gain insights into creating robust React forms with Formik. Delve into managing form states, validation with Yup, and handling submissions to build scalable, efficient forms.

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This course focuses on Formik, a JavaScript library for building forms in React. The ability to handle form data is crucial in modern web development, and Formik simplifies the process by allowing you to create forms with less code. You'll learn how to leverage Formik to create complex and straightforward forms with ease.

You'll start with the basics of Formik and gradually work your way up to more advanced topics. You'll learn how to create form fields, handle validation, manage form states, and submit forms. You'll also learn how to use Formik with other popular libraries like Yup for more advanced validation scenarios. 

By the end of this course, you'll be able to create robust and scalable forms in React using Formik. You'll have a deep understanding of how to manage form states, handle form submissions, and validate user input. Data collection is a key element in information technology and will enable you to build better, more organized forms with less code.

Writing React Forms Like a Pro with Formik

It uses the `name` attribute of the field.

It checks the `touched` object to see if the field has been visited.

How does the `formik.handleChange` method identify the field that called it?

<p>How does the <code>formik.handleChange</code> method identify the field that called it?</p>


```
<input type="text" id="email" {formik.getFieldProps("email")} />
```

```
<input type="text" id="email">
   {formik.getFieldProps("email")}
</input>
```

```
<input type="text" id="email" fieldProps={formik.getFieldProps("email")} />
```

```
<input type="text" id="email" {...formik.getFieldProps("email")} />
```

Given the following input field:

```
<input
  type="text"
  id="email"
  name="email"
  onChange={formik.handleChange}
  onBlur={formik.handleBlur}
  value={formik.values.email}
/>
```

Which is the correct way to rewrite this field using the `formik.getFieldProps` method?


<p>Given the following input field:</p>
<pre><code>&lt;input
  type=&quot;text&quot;
  id=&quot;email&quot;
  name=&quot;email&quot;
  onChange={formik.handleChange}
  onBlur={formik.handleBlur}
  value={formik.values.email}
/&gt;
</code></pre>
<p>Which is the correct way to rewrite this field using the <code>formik.getFieldProps</code> method?</p>


Which of the following components we can use to wrap other Formik components to make the form's state accessible to them?



<p>Which of the following components we can use to wrap other Formik components to make the form’s state accessible to them?</p>


```
{formik.errors.address && formik.touched.address && (
    <small>{formik.errors.address}</small>
)}
```
Which is the correct, more concise way of writing the piece of code above using one of the Formik components?

<pre><code>{formik.errors.address &amp;&amp; formik.touched.address &amp;&amp; (
    &lt;small&gt;{formik.errors.address}&lt;/small&gt;
)}
</code></pre>
<p>Which is the correct, more concise way of writing the piece of code above using one of the Formik components?</p>


What is the default field rendered by Formik's `Field` component?

<p>What is the default field rendered by Formik’s <code>Field</code> component?</p>


```
const initialValues = {
  friends: []
}


{/*...*/}
<Field type="text" name="friends" />
<Field type="text" name="friends" />
<Field type="text" name="friends" />
{/*...*/}
```

```
const initialValues = {
  friends: []
}


{/*...*/}
<Field type="text" name="friends[1]" />
<Field type="text" name="friends[2]" />
<Field type="text" name="friends[3]" />
{/*...*/}
```

```
const initialValues = {
  friends: []
}


{/*...*/}
<Field type="text" name={friends[1]} />
<Field type="text" name={friends[2]} />
<Field type="text" name={friends[3]} />
{/*...*/}
```

```
const initialValues = {
  friends: []
}


{/*...*/}
<Field type="text" name="friends.[1]" />
<Field type="text" name="friends.[2]" />
<Field type="text" name="friends.[3]" />
{/*...*/}
```

```
const initialValues = {
  // ...
  friend2: "",
  friend3: "",
  friend4: "",
  // ...
}


{/*...*/}
<Field type="text" name="friend2" />
<Field type="text" name="friend3" />
<Field type="text" name="friend4" />
{/*...*/}
```

Which is the correct, more concise way of writing the code fragments above?



<pre><code>const initialValues = {
  // ...
  friend2: &quot;&quot;,
  friend3: &quot;&quot;,
  friend4: &quot;&quot;,
  // ...
}


{/*...*/}
&lt;Field type=&quot;text&quot; name=&quot;friend2&quot; /&gt;
&lt;Field type=&quot;text&quot; name=&quot;friend3&quot; /&gt;
&lt;Field type=&quot;text&quot; name=&quot;friend4&quot; /&gt;
{/*...*/}
</code></pre>
<p>Which is the correct, more concise way of writing the code fragments above?</p>


```
<Field name={`branches.${index}.officeInfo.numberOfStaffs`} />
```

```
<Field name={`branches.[${index}].officeInfo.numberOfStaffs`} />
```

```
<Field name={"branches[${index}].officeInfo.numberOfStaffs"} />
```

```
<Field name={`branches${index}.officeInfo.numberOfStaffs`} />
```

```
const initialValues = {
  branches: [
    {
      location: {
        country: "",
        state: "",
      },
      officeInfo: { name: "", numberOfStaffs: 0 },
    },
  ],
};
```

A company needs to collect some information about their different branch offices. They create a form with the `initialValues` above. Which is the correct way to access the `numberOfStaffs` for any of the branches?

<pre><code>const initialValues = {
  branches: [
    {
      location: {
        country: &quot;&quot;,
        state: &quot;&quot;,
      },
      officeInfo: { name: &quot;&quot;, numberOfStaffs: 0 },
    },
  ],
};
</code></pre>
<p>A company needs to collect some information about their different branch offices. They create a form with the <code>initialValues</code> above. Which is the correct way to access the <code>numberOfStaffs</code> for any of the branches?</p>


The `push` method pushes an item to an index in an array while `insert` inserts the item at the end of the array.

The `push` method receives one argument, while `insert` receives no argument.

The `push` method adds an item to the end of an array, while `insert` places an item at a specified index in the array.

The `insert` method is used in forms, while `push` is not.

The `FieldArray` component gives us access to different array helper methods. Two of them are `insert` and `push`. What is the difference between these two?

<p>The <code>FieldArray</code> component gives us access to different array helper methods. Two of them are <code>insert</code> and <code>push</code>. What is the difference between these two?</p>


Quiz

<p>Quiz</p>


Check your understanding of reducing boilerplate code with Formik.

Getting Started

Managing the Form State

Validating Forms

Submitting Forms

Assessment: Formik Essentials — From Managing State to Submission

Reducing Boilerplate

Creating Reusable Form Components

Additional Concepts

Final Assessment

Project: Build a Multi-Step Checkout Form with React and Formik

Quiz: Test on Reducing Boilerplate