Converting Integers to Booleans in JavaScript


In JavaScript, data types are fundamental concepts that we all must understand, like booleans. One common task you might encounter is converting integers to booleans. This might seem odd at first to beginners, but it's more common than you think.

In this Byte, we'll explore how to convert an integer to a boolean in JavaScript.

Integer to Boolean Conversion in JavaScript

JavaScript has a few ways to convert an integer to a boolean. The most straightforward method is to just use the Boolean() function, which converts a value into a boolean.

Here's an example:

let num = 1;
let bool = Boolean(num);
console.log(bool); // Outputs: true

In this case, the integer 1 is converted to the boolean value true. Any non-zero integer will be converted to true, while zero will be converted to false.

Using Double NOT (!!) Operator for Conversion

Another way to convert an integer to a boolean in JavaScript is by using the double NOT (!!) operator. The first exclamation mark first converts the operand to a boolean and then the second exclamation mark negates it. The purpose of this is to use ! to do the boolean conversion.

Here's how you can use it:

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let num = 0;
let bool = !!num;
console.log(bool); // Outputs: false

In this case, the integer 0 is converted to false. This method is often used for its brevity and because it's considered more "JavaScript-y".

Conversion by Comparing with Zero

You can also convert an integer to a boolean by comparing it with zero. If the integer is zero, the result is false; otherwise, it's true.

Let's see how this works:

let num = 5;
let bool = num !== 0;
console.log(bool); // Outputs: true

This method is more explicit and might be easier to understand for people who are new to JavaScript. However, this case may not properly handle scenarios in which the value is null or undefined.

Note: When using comparisons to convert integers to booleans, be aware of JavaScript's loose equality and strict inequality operators. Using the strict inequality operator (!==) ensures that both the value and the type are compared, which can prevent unexpected results.


Converting integers to booleans in JavaScript is a frequent task that can be achieved in several ways. Whether you use the Boolean() function, the double NOT operator, or a comparison with zero depends on your specific needs and coding style.

Last Updated: August 21st, 2023
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