Example to validate input fields only numbers, alphabets, phone etc.

• In the following example, we are observing how to validate a value entered into an input field.
  

    import React from 'react'

    const App = () => {

      const [value, setValue] = React.useState('');

      // Validation functions

      const onlyNumbers = value => /^[0-9]*$/.test(value);

      const onlyAlphabets = value => /^[a-zA-Z]*$/.test(value);

      const phoneNumber = value => /^\d{0,10}$/.test(value);

      return (<>

        <input

          type="text"

          onChange={(event) => {

            const newValue = event.target.value;

            if (phoneNumber(newValue)) {

              setValue(newValue);

            }

          }}

          value={value}

        />

      </>)

    }

    export default App