How Can I Safely Convert String Values ('true' or 'false') to Boolean Values in JavaScript?

Converting Strings to Boolean Values in JavaScript

One may encounter situations where converting a string representing a boolean value, such as 'true' or 'false', into a boolean type is necessary. In JavaScript, there are several approaches to accomplish this:

Recommended Approach

To accurately convert a string to a boolean value, it's essential to avoid implicit type coercion.

var isTrueSet = (myValue === 'true');

This method utilizes the identity operator (===), ensuring that the operands are of the same type. Therefore, 'true' will be assigned to boolean true, while 'false' or an empty string will become boolean false.

For case-insensitive comparisons, consider these options:

var isTrueSet = /^true$/i.test(myValue);<br>var isTrueSet = (myValue?.toLowerCase?.() === 'true');<br>var isTrueSet = (String(myValue).toLowerCase() === 'true');

Methods to Avoid

While the following methods may seem convenient, they are not recommended for boolean conversions:

var myBool = Boolean("false");  // == true<br>var myBool = !!""false"";  // == true

These methods implicitly coerce non-empty strings to true, which may not align with the intended behavior. To avoid confusion, it's preferable to use the methods outlined in the recommended approach.

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