Sometimes, we want to call the useEffect hook conditionally with React.

In this article, we’ll look at how to call the useEffect hook conditionally with React.

Call the useEffect Hook Conditionally with React

To call the useEffect hook conditionally with React, we can check for the condition before running the code in the useEffect callback.

For instance, we write:

import React, { useEffect, useState } from "react";

const wantAnswer = true;

export default function App() {
  const [val, setVal] = useState();

  const getAnswer = async () => {
    const res = await fetch("https://yesno.wtf/api");
    const json = await res.json();
    setVal(json.answer);
  };

  useEffect(() => {
    if (!wantAnswer) {
      return;
    }
    getAnswer();
  }, []);

  return <div>{val}</div>;
}

to call getAnswer only when wantAnswer is true in the useEffect callback.

To do that, we check if wantAnswer is false.

And if it is, we use the return statement to stop running the useEffect callback.

Conclusion

To call the useEffect hook conditionally with React, we can check for the condition before running the code in the useEffect callback.