check if integer javascript code example
Example 1: 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!
}
Example 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!
}
Example 3: javascript is number an integer
Number.isInteger(value)
//returns a Boolean
Example 4: 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 5: 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 6: 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