js check if input is integer code example

Example 1: 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 2: 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

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