como usar o isNumber no javascript es6

Checks if the given argument is a number.

Use typeof to check if a value is classified as a number primitive. To safeguard against NaN, check if val === val (as NaN has a typeof equal to number and is the only value not equal to itself).

const isNumber = val => typeof val === 'number' && val === val;

isNumber(1); // true
isNumber('1'); // false
isNumber(NaN); // false

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