JavaScript: Get the data type

JavaScript Function: Exercise-9 with Solution

Write a JavaScript function which accepts an argument and returns the type.

Note : There are six possible values that typeof returns: object, boolean, function, number, string, and undefined.

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<meta charset=utf-8 />
<title>Detect JavaScript Data Types</title>

JavaScript Code:

function detect_data_type(value)
var dtypes = [Function, RegExp, Number, String, Boolean, Object], x, len;
if (typeof value === "object" || typeof value === "function") 
     for (x = 0, len = dtypes.length; x < len; x++) 
            if (value instanceof dtypes[x])
                return dtypes[x];
    return typeof value;

Sample Output:



Flowchart: JavaScript function: Get the data type

Live Demo:

See the Pen JavaScript -Check a number is prime or not-function-ex- 8 by w3resource (@w3resource) on CodePen.

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JavaScript: Tips of the Day

How to check whether a string contains a substring in JavaScript?

ECMAScript 6 introduced String.prototype.includes:

const string = "foo";
const substring = "oo";


includes doesn't have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns -1 when a substring cannot be found:

var string = "foo";
var substring = "oo";

console.log(string.indexOf(substring) !== -1);

Ref: https://bit.ly/3fFFgZv