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JavaScript typeof Operator (With Example)
JavaScript typeof Operator: In this tutorial, we will learn about the typeof operator in JavaScript with the help of examples.
By IncludeHelp Last updated : July 29, 2023
JavaScript typeof Operator
In JavaScript, the typeof operator is used to get the type of the data/value, variable, or expression. The typeof operator accepts an operand and returns the type of it.
Syntax
Below is the syntax of JavaScript typeof operator:
typeof operand;
or
typeof (operand);
Parameter
- operand - It can be a value, variable/constant name, or an expression whose type you need to find.
Possible return values of typeof
The following are the possible return value of the JavaScript typeof operator (Reference):
| Type | Result |
| Undefined |
"undefined" |
| Null |
"object" |
| Boolean |
"boolean" |
| Number |
"number" |
| BigInt |
"bigint" |
| String |
"string" |
| Symbol |
"symbol" |
| Function |
"function" |
| Any other object |
"object" |
Example
This JavaScript example demonstrates the example of typeof operator. In this example, we are getting and printing the types of different types of variables and variables.
<html>
<head>
<title>JavaScipt Example</title>
</head>
<body>
<script>
var a = 10;
var b = 10.23;
var c = "Hello";
var d;
var e = "10+20";
//printing type of variables
document.write("type of a: " + typeof a + "<br>");
document.write("type of b: " + typeof b + "<br>");
document.write("type of c: " + typeof c + "<br>");
document.write("type of d: " + typeof d + "<br>");
document.write("type of e: " + typeof e + "<br>");
//some of the expressions
document.write(typeof (a+b) + "<br>");
document.write(typeof (a+b+c) + "<br>");
document.write(typeof (a+b+c+d) + "<br>");
document.write(typeof (a+b+c+e) + "<br>");
document.write(typeof (10+20+1.23) + "<br>");
document.write(typeof (NaN) + "<br>");
</script>
</body>
</html>
Output
The output of the above example is:
type of a: number
type of b: number
type of c: string
type of d: undefined
type of e: string
number
string
string
string
number
number
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