Use
const declarations for variables that are never reassigned JS-0242
Anti-pattern
Minor
3 years ago
—
3 years old
'Answers' is never reassigned. Use 'const' instead
22}) {
23 const { theme } = useContextTheme();
24
25 let Answers = new Array(questions.length).fill(''); 26 const [submit, submitting] = useFormspark({
27 formId: formID,
28 });'ans' is never reassigned. Use 'const' instead
46
47 const setAnswersToData = (e) => {
48 const answer = e.target.value;
49 let ans = answers.slice(); 50 ans[surveyPointer] = answer;
51 setAnswers(ans);
52 };'newScrollPosition' is never reassigned. Use 'const' instead
32
33 let newScrollPosition;
34
35 newScrollPosition =36 element.offsetLeft +
37 element.getBoundingClientRect().width / 2 -
38 currentNode.getBoundingClientRect().width / 2;
Description
Variables that are never re-assigned a new value after their initial declaration should be declared with the const keyword.
This prevents the programmer from erroneously re-assigning to a read-only variable, and informs those reading the code that a variable is a constant value.
Bad Practice
let pi = Math.PI
for (let x of xs) {
use(x);
}
let { a, b } = object;
use(a, b);
Recommended
const pi = Math.PI
for (const x of xs) {
use(x);
}
const { a, b } = object;
use(a, b);