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Sep 25th, 2023

How to toggle Boolean in JavaScript?

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Dhairya Shah

Software Engineer

Booleans are a very crucial aspect of any programming language. They represent a binary state, often denoted as true or false. In Javascript, there are several situations where you might need to toggle a boolean variable or switch between its possible values. In this article, we’ll explore various techniques to toggle a boolean in Javascript.

Using the NOT Operator (!)

The simplest and the most common way to toggle a boolean in JavaScript is by using the NOT operator (’!’). This inverts the current value of the boolean variable.

let isToggled = false;
isToggled = !isToggled // Output: true

You can use the NOT operator to toggle boolean variables in a single line of code.

Using Conditional (Ternary) Operator

Another approach to toggle a boolean is by using the conditional (ternary) operator. This method allows you to toggle a boolean variable based on a condition.

let isToggled = true;
isToggled = isToggled ? false : true; // Output: false

The ternary operator checks the current value of isToggled and assigns the opposite value accordingly.

Using XOR Operator (^)

Javascript also supports the XOR (^) operator for toggling boolean values. XOR returns true if the operands are different.

let isToggled = true;
isToggled = isToggled ^ true; // Output: false

However, this method is less common and might be less intuitive than the previous options.

Using Bitwise NOT (~) Operator

Although not recommended for toggling booleans, you can use the bitwise NOT (~) operator in combination with 1 to toggle a boolean value.

let isToggled = true;
isToggled = ~isToggled + 2; // Output: false

This method is less readable and should be avoided for boolean toggling.

Conclusion

In JavaScript, toggling a boolean variable is a fundamental operation used in various programming scenarios. Whether you choose the straightforward NOT operator, the conditional operator, XOR, or the bitwise NOT operator, it’s essential to select the method that best suits your code’s readability and maintainability.

Generally, the NOT operator (!) is the most commonly used and recommended approach for toggling boolean values in JavaScript due to its simplicity and clarity. Always aim for code that is easy to understand and maintain to ensure the longevity of your projects.