Question 1

How do I check if a string is a valid email with is.js?

Accepted Answer

Use the is.email('test@test.com') function, which validates against a built-in regex pattern. Override it with is.setRegexp() if you need custom email formats.

Question 2

is.js vs validator.js for validation?

Accepted Answer

is.js offers a broader range of checks including type, environment, and time validations, while validator.js focuses more on string and format validations. Choose is.js for comprehensive utility or validator.js for lightweight string checks.

Question 3

How to override regex patterns in is.js?

Accepted Answer

Use the configuration method is.setRegexp(/newpattern/, 'name') to replace existing regexps, as shown in the README. This allows custom validations but requires manual setup.

Question 4

Does is.js work with Node.js?

Accepted Answer

Yes, most functions like type checks and regex validations work in Node.js, but environment detection functions are browser-only and unavailable in Node modules.

Question 5

How to check multiple conditions with is.js?

Accepted Answer

Use the 'all' or 'any' interfaces, e.g., is.all.positive([1,2,3]) for all positive numbers, or is.any.url(['http://test.com', 'invalid']) for any valid URL.

Question 6

Can I use is.js in a React app for form validation?

Accepted Answer

Yes, is.js can handle validation logic, but for better integration with React state and forms, consider combining it with libraries like Formik or using it for backend validation checks.

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