React Version

React versions matter because APIs changed. Class components were the default for years. Hooks arrived in 16.8. React 18 added createRoot and concurrent rendering. In a viva, say the era you write: function components + hooks, React 18+ createRoot — not ReactDOM.render.

Don’t mug a patch like 18.2.0 as if it were history. Check package.json on a real project. react and react-dom should share the same major. Mixing 17 and 18 is a support headache.

React Version — output — three era lines. Interview wants 18+ createRoot, not a random patch.

Exam tip

Hooks era + createRoot. Check package.json.

Example

// Versions
console.log("React 16: class + early hooks");
console.log("React 18: concurrent + createRoot");
console.log("Check package.json → react version");

React Version — output: three era lines. Interview wants 18+ createRoot, not a random patch.

Short notes

Def16.8 hooks. 18 createRoot.
RuleMatch react and react-dom majors.
TrapReciting ReactDOM.render as current.

React Version

Don’t mug a patch like 18.2.0 as if it were history. Check package.json on a real project. react and react-dom should share the same major. Mixing 17 and 18 is a support headache.

React Version — output — three era lines. Interview wants 18+ createRoot, not a random patch.

Exam tip

Hooks era + createRoot. Check package.json.

Example

// Versions
console.log("React 16: class + early hooks");
console.log("React 18: concurrent + createRoot");
console.log("Check package.json → react version");

React Version — output: three era lines. Interview wants 18+ createRoot, not a random patch.

Short notes

Def16.8 hooks. 18 createRoot.
RuleMatch react and react-dom majors.
TrapReciting ReactDOM.render as current.

React Version

Example

Short notes

Questions

React Version

Example

Short notes

Questions