# react.useref

`useRef` returns a mutable ref object whose `.current` property is initialized to the passed argument (`initialValue`). The returned object will persist for the full lifetime of the component.

```jsx
function TextInputWithFocusButton() {
  const inputEl = useRef(null);
  const onButtonClick = () => {
    // `current` points to the mounted text input element
    inputEl.current.focus();
  };
  return (
    <>
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus the input</button>
    </>
  );
}
```

Keep in mind that `useRef` *doesn’t* notify you when its content changes. Mutating the `.current` property doesn’t cause a re-render. If you want to run some code when React attaches or detaches a ref to a DOM node, you may want to use a [callback ref](https://reactjs.org/docs/hooks-faq.html#how-can-i-measure-a-dom-node) instead.