React 核心 API

主要API

const React={
    Children:{
        map,
        forEach,
        count,
        toArray,
        only
    },
    createRef,
    Component,
    PureComponent,
    
    createContext,
    forwordRef, 
    lazy,
    memo,
    
    // hooks
    useEffect,
    useLayoutEffect,
    useState,
    useReducer,
    useMemo,
    useCallback,
    useContext,
    useRef,
    useImperativeHandle, // 配合 forwordRef 一起使用
    useDebugValue,
    
    Fragment: REACT_FRAGMENT_TYPE,
    Profile: REACT_PROFILE_TYPE,
    StrictMode: REACT_STRICT_MODE_TYPE,
    Suspense: REACT_SUSPENSE_TYPE,
    
    createElement: __DEV__ ? createElementWithValidation : createElement,
    cloneElement: __DEV__ ? cloneElementWithValidation : cloneElement,
    createFactory: __DEV__ ? createFactoryWithValidation : createFactory,
    isValidElement,
    
    version: ReactVersion,
}

最核心的api：

• React.createElement：创建虚拟DOM
• React.Component：实现自定义组件
• ReactDOM.render：渲染真实DOM