Question 230886 in Javascript Question posted in
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Javascript – Why there's always an empty element at the first index?

Whenever i tried to put something in my todoList there’s alwasy an empty element at first indext Why it is happening?

const [todoList, setTodoList] = useState([]);
  
  const addToList = (inputText) => {
    if (inputText === "") {
      alert("List is Empty")
    }else{
       setTodoList([inputText, ...todoList])
    }
    console.log(todoList);
  };

  const addList = (inputText) => {
    addToList(inputText);
  };

const [todoList, setTodoList] = useState([]);
  

  const addToList = (inputText) => {
    if (inputText === "") {
      alert("List is Empty")
    }else{
       setTodoList([...todoList, inputText])
    }
    console.log(todoList);
  };

  const addList = (inputText) => {
    addToList(inputText);
  };

i tried it also but it’s not working

Tags:

2

Answers


  1. 0

    Your

    setTodoList([inputText, ...todoList])

    is taking the todoList using closure, so it is taking the same one every time.

    You need to do something like:

    setTodoList(todoList => [inputText, ...todoList])
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  2. 0

    I think adding useEffect() might do the trick:

    const [todoList, setTodoList] = useState([]);

const addToList = (inputText) => {
  if (inputText === "") {
    alert("List is Empty");
  } else {
    setTodoList([inputText, ...todoList]);
  }
};

useEffect(() => {
  console.log(todoList);
}, [todoList]);

const addList = (inputText) => {
  addToList(inputText);
};
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