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);
NaN reserved word
NaN means Not a Number, these cannot be used to perform the mathematical operation.
var fruit = "orange"; fruit=fruit*2;
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