js check if vat is a int 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: js check if string is int

function isNumeric(str) {

	// Check if input is string
	if (typeof str != "string")
    	return false

	// Use type coercion to parse the _entirety_ of the string
    // (`parseFloat` alone does not do this).
	// Also ensure that the strings whitespaces fail
	return !isNaN(str) && 
		!isNaN(parseFloat(str)) 
}