How can I set the value of a select input in React?

Adding selected to an option

A very common way of setting a <select> input's value is by adding a selected attribute to one of its <option> elements. For example:

const Select = ({ values, callback, selected }) => {
  return (
    <select
      disabled={disabled}
      readOnly={readonly}
      onChange={({ target: { value } }) => callback(value)}
    >
      {values.map(([value, text]) => (
        <option selected={selected === value} value={value}>
          {text}
        </option>
      ))}
    </select>
  );
}

Setting value for the select

While this approach closely resembles HTML and feels intuitive, there is an easier way to do the same thing. React provides us with a shared API between <input type="text">, <textarea> and <select> where we can use value or defaultValue (depending if the input is controlled or not) to set the field's value.

Using this API, we minimize the effort of checking for the selected value, as well as making the code easier to read and update as necessary. Here's an example:

const Select = ({ values, callback, selected }) => {
  return (
    <select
      disabled={disabled}
      readOnly={readonly}
      defaultValue={selected}
      onChange={({ target: { value } }) => callback(value)}
    >
      {values.map(([value, text]) => (
        <option value={value}>
          {text}
        </option>
      ))}
    </select>
  );
}

Note that the above implementation uses defaultValue, therefore it implies that the component is uncontrolled. You can convert this Select component into a controlled component by using value instead of defaultValue.

For a more detailed explanation of the component, as well as usage examples, you can check out the Select component.