JavaScript: Return true if the given value is a number, false otherwise

JavaScript fundamental (ES6 Syntax): Exercise-105 with Solution

Write a JavaScript program that returns true if the given value is a number, false otherwise.

• Use parseFloat() to try to convert n to a number.
• Use !Number.isNaN() to check if num is a number.
• Use Number.isFinite() to check if num is finite.
• Use Number() and the loose equality operator (==) to check if the coercion holds.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n) && Number(n) == n;
console.log(validateNumber('200'));
console.log(validateNumber('10'));
console.log(validateNumber('abc'));

Sample Output:

true
true
false

Pictorial Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-105-1 by w3resource (@w3resource) on CodePen.

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