javascriptreactjsreact-hooks

Checking for undefined variables in Js

can someone plz explain why "Shululu" is printed in this code?

const [selectedFiles, setSelectedFiles] = useState([undefined]);     
useEffect(() => {
  if (typeof selectedFiles !== undefined)
    console.log("shululu")
  setFileInfos(selectedFiles);
}, [selectedFiles]);
Solution

  • Cause selectedFiles is an array that contains undefined. You should just do useState() if you want it to be null