how to check if a variable is number in javascript code example

Example 1: 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!
}

Example 2: javascript check if a value is an int

// The Number.isInteger() checks to see if the passed value is an integer
// Returns true or false

Number.isInteger(2); //True
Number.isInteger(90); //True
Number.isInteger("37"); //False
Number.isInteger(false); //false

Example 3: javascript check if variable is number

function isNumber(n) {
  return !isNaN(parseFloat(n)) && !isNaN(n - 0);
}

Example 4: 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")
else
    alert("data is not an integer")