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!
}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(' '); // falsejavascript check if variable is number
function isNumber(n) {
return !isNaN(parseFloat(n)) && !isNaN(n - 0);
}check if a variable is a number in javascript
// as test cases we have two variables of which 1 is a number and the second one is a string
let x = 7;
let y = "hello"
let result1 = !Number.isNaN(x) // true
let result2 = !Number.isNaN(y) // flaseTo check if a value is a number in JavaScript
const value = 2
isNaN(value) //false
isNaN('test') //true
isNaN({}) //true
isNaN(1.2) //falsejs 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")Copyright © 2021 Codeinu
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