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Start your free trialAbhimanu Saharan
Front End Web Development Techdegree Student 36 PointsuseState hook setting different value than what is passed into setState()
I have a select menu with some options. When I change the option in select menu I am setting the state of currentValue using setNewValue(event.target.value) and logging the new value of variable to the console.
However the value set for the variable is different from the value I am passing into setNewValue.
const classGrades = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let [classGrade, setClassGrade] = useState(1);
let classSelect = () => {
return (
<div>
<select value={classGrade} onChange={(e) => {
setClassGrade(e.target.value)
console.log(`I selected ${e.target.value}, so classgrade is now ${classGrade}`)
}}>
{classGrades.map(g => <option key={g} value={g}>{g}</option>)}
</select>
</div>
)
}
1 Answer
Clayton Perszyk
Treehouse Moderator 48,850 PointsLooks like the issue is this:
useStateis an asynchronous hook and it doesn’t change the state immediately, it has to wait for the component to re-render.
see this article for more info: https://javascript.plainenglish.io/why-you-shouldnt-always-use-usestate-658994693018#:~:text=TL%3BDR%3A%20useState%20is%20an,t%20trigger%20a%20re%2Drender.