Answers for "javascript check if variable is number"

38

javascript check if number

//Updated dec 2020
// 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 December-12-2020
-2

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
0

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
4

javascript check if variable is number

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

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

Code answers related to "javascript check if variable is number"

Code answers related to "Javascript"

Browse Popular Code Answers by Language