react form example

Example 1: form in react

import React, { useState } from "react";
import "./styles.css";
function Form() {
  const [firstName, setFirstName] = useState("");
  const [lastName, setLastName] = useState("");
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  return (
    <form>
      <input
        value={firstName}
        onChange={e => setFirstName(e.target.value)}
        placeholder="First name"
        type="text"
        name="firstName"
        required
      />
      <input
        value={lastName}
        onChange={e => setLastName(e.target.value)}
        placeholder="Last name"
        type="text"
        name="lastName"
        required
      />
      <input
        value={email}
        onChange={e => setEmail(e.target.value)}
        placeholder="Email address"
        type="email"
        name="email"
        required
      />
      <input
        value={password}
        onChange={e => setPassword(e.target.value)}
        placeholder="Password"
        type="password"
        name="password"
        required
      />
      <button type="submit">Submit</button>
    </form>
  );
}
export default Form;

Example 2: react text input onchange

class NameForm extends React.Component {
  constructor(props) {
    super(props);
    this.state = {value: ''};
    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  handleChange(event) {    this.setState({value: event.target.value});  }
  handleSubmit(event) {
    alert('A name was submitted: ' + this.state.value);
    event.preventDefault();
  }

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        <label>
          Name:
          <input type="text" value={this.state.value} onChange={this.handleChange} />        </label>
        <input type="submit" value="Submit" />
      </form>
    );
  }
}

Example 3: dynamic forms in react

class App extends React.Component {
  constructor(props) {
    super(props);
    this.state = { values: [] };
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  createUI(){
     return this.state.values.map((el, i) => 
         <div key={i}>
    	    <input type="text" value={el||''} onChange={this.handleChange.bind(this, i)} />
    	    <input type='button' value='remove' onClick={this.removeClick.bind(this, i)}/>
         </div>          
     )
  }

  handleChange(i, event) {
     let values = [...this.state.values];
     values[i] = event.target.value;
     this.setState({ values });
  }
  
  addClick(){
    this.setState(prevState => ({ values: [...prevState.values, '']}))
  }
  
  removeClick(i){
     let values = [...this.state.values];
     values.splice(i,1);
     this.setState({ values });
  }

  handleSubmit(event) {
    alert('A name was submitted: ' + this.state.values.join(', '));
    event.preventDefault();
  }

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
          {this.createUI()}        
          <input type='button' value='add more' onClick={this.addClick.bind(this)}/>
          <input type="submit" value="Submit" />
      </form>
    );
  }
}

ReactDOM.render(<App />, document.getElementById('container'));

Example 4: html select react

class FlavorForm extends React.Component {
  constructor(props) {
    super(props);
    this.state = {value: 'coconut'};
    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
  }

  handleChange(event) {    this.setState({value: event.target.value});  }
  handleSubmit(event) {
    alert('Your favorite flavor is: ' + this.state.value);
    event.preventDefault();
  }

  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        <label>
          Pick your favorite flavor:
          <select value={this.state.value} onChange={this.handleChange}>            <option value="grapefruit">Grapefruit</option>
            <option value="lime">Lime</option>
            <option value="coconut">Coconut</option>
            <option value="mango">Mango</option>
          </select>
        </label>
        <input type="submit" value="Submit" />
      </form>
    );
  }
}

Example 5: form in react js

// functional react form 

import React, { useState } from "react";

export function Form() {
	const [name, setName] = useState("");


	const handleSubmit = (evt) => {
		evt.preventDefault();
		alert(`Submitting Name ${name}`)
	}
	const changeName = (e) => {
		setName(e.target.value)
	}
	return (
		<form onSubmit={handleSubmit}>
			<br />
			<br />
			<label>
				Frirst Name:
        <input
					type="text"
					value={name}
					onChange={changeName}
				/>
			</label>
			<input type="submit" value="Submit" />
		</form>
	);
}
export default Form;

Example 6: react hook form example stack overflow

import React from 'react';
import ReactDOM from 'react-dom';
import { connect } from "react-redux";
import useForm from 'react-hook-form';

function SampleForm() {
  const { register, handleSubmit } = useForm();
  const onSubmit = data => {
    alert(JSON.stringify(data));
  };

  return (
    <div className="App">
      <form onSubmit={handleSubmit(onSubmit)}>
        <div>
          <label htmlFor="firstName">First Name</label>
          <input name="firstName" placeholder="bill" ref={register} />
        </div>

        <div>
          <label htmlFor="lastName">Last Name</label>
          <input name="lastName" placeholder="luo" ref={register} />
        </div>

        <div>
          <label htmlFor="email">Email</label>
          <input name="email" placeholder="[email protected]" type="email" ref={register} />
        </div>
        <button type="submit">Submit</button>
      </form>
    </div>
  );
}

class Sample extends Component {
  constructor(props) {
    super(props);
  }

  render() {
    return <SampleForm />;
  }
}

export default connect()(Sample);

const rootElement = document.getElementById('root');
ReactDOM.render(<Sample />, rootElement);