Check if array has only one match
JavaScript, Array · Jul 4, 2021
Checks if an array has only one value matching the given function.
- Use
Array.prototype.filter()in combination withfnto find all matching array elements. - Use
Array.prototype.lengthto check if only one element matchesfn.
const hasOne = (arr, fn) => arr.filter(fn).length === 1;hasOne([1, 2], x => x % 2); // true
hasOne([1, 3], x => x % 2); // false
