Dec 3, 2015 · JavaScript's OR operator doesn't return boolean true/false values like other languages. Rather it checks if the left evaluates to true when type casted to boolean, If true, it returns the value rather than a boolean. If false, then it …

Jan 4, 2024 · to check for undefined and null in javascript you need just to write the following : if (!var) { console.log("var IS null or undefined"); } else { console.log("var is NOT null or undefined"); }

Jan 11, 2016 · It should be null when it isn't needed. Later, I get this check in the same function: console.log(parent == null); var siblingCount = parent.next().children().length; if (siblingCount === 0) parent.removeClass('group'); parent.addClass('normal-item');

The if/else statement executes a block of code if a specified condition is true. If the condition is false, another block of code can be executed. The if/else statement is a part of JavaScript's "Conditional" Statements, which are used to perform different actions based …

Now let‘s explore the different ways to actually check if a variable is null in JavaScript. Checking for Null with If/Else Statements. The simplest and most straightforward way to check if a variable is null is using good old if/else statements. Let‘s check if a variable is null:

Aug 28, 2024 · Lodash _.isNull () method is used to find whether the value of the object is null. If the value is null then returns true otherwise it returns false. Example: In this example, we are checking whether the given value is null or not by the use of the _isNull () method. Output:

To determine whether a value is specifically null, the triple equality operator is the best method available. We can also use this in conjunction with Object.is() to determine a null value. Here’s a quick overview of both approaches.

Sep 11, 2024 · Using the typeof operator, JavaScript checks if a variable is not null by verifying typeof variable !== ‘undefined’ && variable !== null. This approach ensures the variable exists and is not explicitly set to null, promoting reliable code execution.

Mar 21, 2017 · So use if(string1 === '') instead of writing if(string1.length==0). Solution: Then you can simply use the following condition: //Your code here. Explanation: It will be true if one of the two strings is null or empty, in other words if any of the …

Jan 5, 2024 · We can use the strict equality operator (===) in JavaScript to check if a variable is explicitly set to null. It not only checks for the value of the two variables to be equal but also checks for their types to be the same.