Answers for "check if a variable is a number javascript"


javascript check if number

// The first 2 Variations return a Boolean
// They just work the opposite way around

// IsInteger
if (Number.isInteger(val)) {
	// It is indeed a number

// isNaN (is not a number)
if (isNaN(val)) {
	// It is not a number

// Another option is typeof which return a string
if (typeof(val) === 'number') {
	// Guess what, it's a bloody number!
Posted by: Guest on March-15-2020

javascript check if number

function isNumber(n) { return /^-?[\d.]+(?:e-?\d+)?$/.test(n); } 


isNumber('123'); // true  
isNumber('123abc'); // false  
isNumber(5); // true  
isNumber('q345'); // false
isNumber(null); // false
isNumber(undefined); // false
isNumber(false); // false
isNumber('   '); // false
Posted by: Guest on May-21-2020

javascript check if variable is number

function isNumber(n) {
  return !isNaN(parseFloat(n)) && !isNaN(n - 0);
Posted by: Guest on May-22-2020

check if a variable is a number in javascript

// as test cases we have two variables of which 1 is a number and the second one is a string
let x = 7;
let y = "hello"
let result1 = !Number.isNaN(x) // true
let result2 = !Number.isNaN(y) // flase
Posted by: Guest on June-01-2021

To check if a value is a number in JavaScript

const value = 2
isNaN(value) //false
isNaN('test') //true
isNaN({}) //true
isNaN(1.2) //false
Posted by: Guest on April-19-2021

js is variable int

// The === operator is used for checking
// the value and the type of a variable

var data = 1;

if (data === parseInt(data, 10))
    alert("data is integer")
    alert("data is not an integer")
Posted by: Guest on October-09-2020

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