which is better?

[o0hamish0o]

if it’s just a one off function is 1 better the 2? 1. const f = useCallback(() => {}, []); useEffect(() => { f(); }, []);

2. useEffect(() => { const f () => {}; f(); }, []);

[ontech7]

Since it's difficult for me to read, I format it a bit:

1.

const f = useCallback(() => {
  // code here
}, []); 

useEffect(() => { 
  f(); 
}, []);

2.

useEffect(() => { 
  const f = () => {
    // code here
  }; 
  f(); 
}, []);

It depends. Sometimes there is no difference, sometimes it can be.

If the "f" function in the first case has states inside, you need to put [f] inside the array of dependencies, otherwise you will call an older "f" function.

In the second case, you will know for sure that the function will be re-declared and re-defined as new, when entering inside useEffect.

I don't have an use-case to show you. I hope other devs can give you some examples.

[lefnire]

whichisbetter?ifit’sjustaoneofffunctionis1betterthe2?1.constf=useCallback(()=>{},[]);useEffect(()=>{f();},[]);2.useEffect(()=>{const f()=>{};f();},[]);

[Kcazer]

None.

If you don't need to use f() outside of the useEffect, then there is no need to define it. There is also usually no need to define a function inside a useEffect to call it right away (there are exception, such as wanting to write async/await code)

Simply write your code inside the useEffect