JavaScript: Check if a given argument is a number
JavaScript fundamental (ES6 Syntax): Exercise-195 with Solution
Write a JavaScript program to check if a 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).
Sample Solution:
JavaScript Code:
// Define a function 'isNumber' that checks if the given value 'val' is a number
const isNumber = val =>
// Check if the type of 'val' is 'number'
typeof val === 'number';
// Test cases to check if the values are numbers
console.log(isNumber('1')); // false (the value is a string, not a number)
console.log(isNumber(1)); // true (the value is a number)
Output:
false true
Visual Presentation:
Flowchart:
Live Demo:
See the Pen javascript-basic-exercise-195-1 by w3resource (@w3resource) on CodePen.
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