What's the best way to parse string boolean values into actual booleans in JavaScript?

[liamj]

I’m working with a web form that has hidden input fields containing boolean data. When users make selections from a dropdown menu, the form gets updated with boolean values. The problem is that these boolean values turn into strings once they’re stored in the input fields.

Right now I’m checking the string content to figure out if it’s true or false:

var formValue = document.getElementById('myForm').ACTIVE_FLAG.value;
var isActive = formValue == 'true';

This works but feels like there should be a cleaner approach. Are there any built-in JavaScript methods or better techniques for converting string representations of booleans back into proper boolean types? I’ve seen different approaches online but want to know what’s considered the most reliable method.

[RunningTiger]

Hit this exact problem last year with localStorage booleans. After trying different methods, I went with JSON.parse() and it’s been solid. var isActive = JSON.parse(formValue); converts ‘true’ to true and ‘false’ to false perfectly, plus it throws errors on bad input so you catch data problems early. Way cleaner than comparison operators. Just heads up - it’ll throw a SyntaxError if the string isn’t valid JSON, so wrap it in try-catch if your data’s sketchy. Been running this in production for months with zero issues.

[emcarter]

I just use the !! operator with basic logic. Something like var isActive = formValue !== 'false' && !!formValue; handles most situations. Deals with empty strings and undefined without issues. I’ve used this approach for years and never run into the weird edge cases you get with JSON parsing.

[JackHero77]

Another solid approach is using a ternary operator with strict comparison: var isActive = formValue === 'true' ? true : false; This skips JSON parsing overhead and gives you full control over the conversion. I’ve used this pattern for three years across different projects and it handles edge cases better than loose equality. The big advantage? It’s predictable - anything that isn’t exactly ‘true’ becomes false, which is usually what you want for form validation. If you’re doing this conversion a lot, consider a utility function like function toBool(str) { return str === 'true'; } instead.