深入理解 React Hooks：从原理到实践

前言

React Hooks 自 16.8 版本引入以来，彻底改变了 React 组件的编写方式。

useState 的底层实现

function useState<T>(initialState: T): [T, (newState: T) => void] {
  const hook = getCurrentHook();
  if (!hook.initialized) {
    hook.state = initialState;
    hook.initialized = true;
  }
  const setState = (newState: T) => {
    hook.state = newState;
    scheduleRender();
  };
  return [hook.state, setState];
}