This is a short guide on how to check if a variable or value if an object using JavaScript. In order to do this, we can use thetypeofoperator, which returns the data type of a given value in a string format. Take a look at the following JavaScript snippet: //An example object. va...
Unlike Array.isArray() method which we used for checking if a variable is an array, there is no Object.isObject() method in JavaScript.The quickest and most accurate way to check if a variable is an object is by using the Object.prototype.toString() method....
Javascript a value is an object1 2 3 4 5 6 7 8 9 10 11 12 13 // Returns if a value is an object let obj = { siteName: 'W3Docs', }; let str = 'W3Docs'; function isObject(objValue) { return objValue && typeof objValue === 'object' && objValue.constructor === Object...
If the variable is an array, the comparison will evaluate to true. const myArr = [1, 2, 3]; const myObj = {name: "John"}; Object.getPrototypeOf(myArr) === Array.prototype; // output: true Object.getPrototypeOf(myObj) === Array.prototype; // output: false JavaScript Copy And ...
In JavaScript, a value can either be a primitive or an object. Therefore, you can check if a value is a JavaScript primitive (as opposed to being an object) using the following check: !(value instanceof Object) You may see value !== Object(value) as a means to check for prim...
A variable is calledundefinedif it is declared without being assigned an initial value. Below are multiple ways we can do this in JavaScript. Directly Compare a Variable Withundefinedto Check Undefined in JavaScript varx;if(x===undefined){text='x is undefined';}else{text='x is defined';}...
JavaScript has 9 types in total: undefined boolean number string bigint symbol object null (typeof() shows as object) function (a special type of object) To verify if a variable is a number, we simply we need to check if the value returned by typeof() is "number". Let's try it ...
In JavaScript, the typeof operator is the most used method to check the type of any variable. Alternatively, you can use the typeof() method: let myString = 'John Doe'; typeof myString; // string typeof(myString); // string If used with a string, the typeof operator returns "...
How to Check if a Variable is an Array in JavaScript - To check if a variable is an array in Javascript is essential to handle data appropriately. We will discuss three different approaches to check if a variable is an array or not. We are having an arra
JavaScript interpreter returns undefined when users access a variable or object property that they have not yet initialized. When a variable is declared or initialized, but users do not assign any value to it, the interpreter automatically displays undef