Controlled Inputs interview questions

Build an accordion component with stacked sections whose content panels expand and collapse on click.

Build a textarea with a live character counter that warns as it nears a maximum length.

Build a contact form that posts the user's name, email, and message to a backend endpoint.

Build a small form that books either a one-way or return flight, with validation tying the two date fields together.

Build a calculator that computes the monthly payment for a loan based on principal, rate, and term inputs.

Build a password field with a live strength meter that scores the input as you type.

Build a widget that converts between Celsius and Fahrenheit, updating either field as the other changes.

Build a star rating component where users click a star to set the rating shown by filled icons.

Implement a hook that lets one component work both controlled and uncontrolled, deciding the mode from its props.

Implement a hook that manages a controlled input value alongside its dirty and touched flags.

Build a six-cell auth code input that handles typing, paste, backspace, and arrow-key navigation across fields.

Build a nested checkbox tree where parent state reflects its children and toggling a parent cascades down.