js value to boolean
JS Value to Boolean
JavaScript is a loosely typed language which means that values can have different types. Inevitably, you may come across a situation where you need to convert a value to a boolean for better understanding and handling of the code.
Using Boolean() Function
The most commonly used method for converting a value to a boolean in JavaScript is using the Boolean() function. Here is an example:
const value = "Hello World";
const booleanValue = Boolean(value);
console.log(booleanValue); // true
The Boolean() function converts the value to a boolean and returns it. The above example will return true as "Hello World"
is a non-empty string and thus, a truthy value.
Using Double NOT(!!) Operator
Another way of converting a value to a boolean in JavaScript is by using the double NOT(!!) operator. Here is an example:
const value = "Hello World";
const booleanValue = !!value;
console.log(booleanValue); // true
The double NOT(!!) operator converts the value to a boolean as well, but in a more concise way. The above example will return true for the same reason as before.
Considerations
It is important to understand that not all values can be converted to a boolean in the same way. In JavaScript, the following values are considered falsy:
- false
- 0
- "" (empty string)
- null
- undefined
- NaN
Any other value not listed above is considered a truthy value. So, be careful when using boolean conversions in your code and always test it thoroughly.