Checks if str is of type "string", which applies to string literals. It does not return "string" for new String() because new String() is an object. Fallback: return "another type"; Handles cases where str is neither a string literal nor a String object (e.g., numbers, arrays, et...
Alternatively, it can also be used as typeof() method in JavaScript.Syntax:typeof(variable); Example 1:str = "This is my place."; if (typeof str == String) { console.log('The variable is a String.'); } else { console.log('The variable is not a String.'); } ...
// Sample variablevarmyVar='Hello';// Test if variable is a stringif(typeofmyVar==='string'){alert('It is a string.');}else{alert('It is not a string.');} You can also define a custom function to check whether a variable is a string or not. ...
If you don't want it to throw aTypeError, you can add an extra check: letvalue;value// 👈 null and undefined check&&Object.keys(value).length===0&&value.constructor===Object;value=null;// nullvalue=undefined;// undefined Perfect, no error is thrown 😁 ...
if(typeofmyVar==="string"){console.log("myVar is a string");}else{console.log("myVar is not a string");} Another way to check if a variable is a string is to use theinstanceofoperator, which returns true if an object is an instance of a particular constructor. For example, the ...
How to Check If an Object Is Empty in JavaScript Use Object.keys Loop Over Object Properties With for…in Use JSON.stringify Use jQuery Use Underscore and Lodash Libraries 1. Use Object.keys Object.keys will return an array, which contains the property names of the object. If the length of...
Below is an example to find if the string is a palindrome using JavaScript String and Array Methods ? Open Compiler // Function to check for Palindrome function isPalindrome(str) { const lowerCaseStr = str.toLowerCase(); const modifiedStr = lowerCaseStr.replace(/[\W_]/g, ''); const re...
The JSON.stringify method is used to convert a JavaScript object to a JSON string. So we can use it to convert an object to a string, and we can compare the result with {} to check if the given object is empty. Let’s go through the following example. 1 function isEmptyObject(obj...
includes method is very easy to use and comes with additional options like search position. In older versions of Javascript, we can add a polyfill for include method if (!String.prototype.includes) { Object.defineProperty(String.prototype, 'includes', { value: function(substring, searchposi...
For JavaScript objects, there is no built-in .length or .isEmpty method available to check if they are empty. Here are 4 different methods that you can use to make sure that a given object does not have its own properties: Object.entries() Method The Object.entries() method takes an ...