Search Here

Javascript Numbers | Assignment, Type Cheking and NaN (Not a Number) keyword

Javascript Numbers | Assignment, Type Checking and NaN

In Javascript, Numbers can be directly assigned to a variable without any need of declaring data-type.
There is also another option were number object is created using object of class Number.
This object has various methods and properties related to numbers and formatting which will be discussed in another post.

This post will cover topics related to assignment, condition and type checking of Numbers.

Assigning integer and float value to a number.

var salary = 25000; //this is integer value
var average = 2.569; //this is float value

typeof Reserved Word

Using typeof is a reserved word that used to get the type of variable whether it may
be integer, float, object, array and strings etc.

var name = "John";
var age = 21;
var total_marks = 456.26;

console.log(typeof name);
console.log(typeof age);
console.log(typeof total_marks);

JavaScript Numbers using type of keyword

NaN reserved word

NaN means Not a Number, these cannot be used to perform the mathematical operation.

var fruit = "orange";
fruit=fruit*2;

JavaScript Number multiplying strings with numbers

By using with if conditions.

var fruit = "orange";
if(isNaN(fruit)){
    console.log("This is not a number");
}else{
    console.log("This is a number");
}

//Console Output
This is not a number

Using `===` equal to operator

Using `===` will not only check if the value is equal but also check if is of equal type.

using `==` equal to operator.

x = "10";
y = 10;
if(x==y){
    console.log("Value of x is equal to y");
}else{
    console.log("Value of x is not equal to y");
}

//Console Output
Value of x is equal to y

using `===` equal to operator.

x = "10";
y = 10;
if(x===y){
    console.log("Value of x is equal to y");
}else{
    console.log("Value of x is not equal to y");
}

//Console Output
Value of x is not equal to y

Related Posts