javascript validate number code example

Example 1: integer check in javascript

var a=Number.isInteger(5); //True
var b= Number.isInteger(01); //True
var c=Number.isInteger("10"); //False

console.log(a,b,c);  //true true false

Example 2: check if input is a number javascript

// Another option is typeof which return a string
if (typeof(val) === 'number') {
	// Guess what, it's a bloody number!
}

Example 3: 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 4: javascript check if variable is number

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

Example 5: check to see if number is a decimal javascript

The Number. isInteger() method determines whether a 
value an integer. 
This method returns true if the value is of the type 
Number, and an integer (a number without decimals). 
Otherwise it returns false.

Example 6: validatorjs number

const validationRule = 'required|numeric';