react hook useEffect throwing Assignment to const variable error

Question

I am working on some code, and I am stuck on this error. I have not seen it come up before in my other projects, and so I am not sure why it is here. I am using the useEffect hook, and I want to update it when a user chooses an option from a drop down. What happens is that when a user chooses an option, i get the following error TypeError: Assignment to constant variable. . I understand that it is saying that I am trying to update a constant which cant happen, but I dont get why. Unfortunalty,

I can not determine how to properly render my code, but the next two lines are the lines of code that I am having the issue with. These are then followed by the full code that I am working on.

const [TitleId, setTitleId] = useState(0); const TitleSelect = event =>{ console.log(event.target.value); setTitleId=(32); };

import React, {useState,useEffect} from 'react';
// import '../app.css';

const Header = props=> {
const [TitleList, setTitleList] = useState([]);
const [TitleId, setTitleId] = useState(0);

useEffect(()=>{
    console.log('first start');
    setTitleList(
        props.data.map((title,index)=>({
            title: title.title,
            id: index
        }))
    )
},[])
const TitleSelect = event =>{
    console.log(event.target.value);
    setTitleId=(32);
};

let content = (
    <select
    onChange={TitleSelect}>
    {TitleList.map(title=>(
        <option key={title.id} value={title.id}>
                {title.title}
                </option>
    ))}

    </select>)  
return(content);
}
export default Header;

Any suggestions or advice is greatly appreciated.

Answer 1

setTitleId=(32); is causing error you meant setTitleId(32); instead.

By doing setTitleId=(32) you were trying to assign a value to a const declaration that holds reference to a function pointer returned by useState thus you got Assignment to const variable error