React类组件中是否可将state重命名为globalState等自定义名称？

Hey there! Let's unpack your two key questions to clear up any confusion you're having with React.

1. Your Understanding of Child Components Modifying Parent State #

Your current understanding is a bit off—here's the correct breakdown:

• React doesn't automatically pass a "state modification mechanism" when sending parent state to a child component. To let a child update a parent's state, you have to explicitly pass a function from the parent to the child via props—this function will trigger the parent's setState call when invoked by the child.
• Here's a quick example to illustrate:

  // App.js (Parent Component)
  class App extends React.Component {
    state = { globalCount: 0 };
  
    // Define a method that updates the parent's state
    incrementGlobalCount = () => {
      this.setState(prevState => ({ globalCount: prevState.globalCount + 1 }));
    };
  
    render() {
      // Pass both the state value AND the update function to the child
      return (
        <Home 
          currentCount={this.state.globalCount}
          onIncrement={this.incrementGlobalCount}
        />
      );
    }
  }
  
  // Home.js (Child Component)
  class Home extends React.Component {
    render() {
      // Call the parent's function when the button is clicked
      return (
        <button onClick={this.props.onIncrement}>
          Click to increase global count: {this.props.currentCount}
        </button>
      );
    }
  }
  

• This follows React's one-way data flow rule: children can't directly modify parent state/props. Instead, they signal the parent to make changes using the functions provided via props.

2. Can You Rename the Component's state Property? #

This depends on whether you're using class components or function components, and since you mentioned using state={} and this.state, let's focus on your class component scenario first:

• For class components: this.state is not just a convention—it's required by React
  You might have tried renaming it and seen it "work" initially, but that's a false positive. React only tracks changes to this.state and triggers re-renders when you update it via this.setState(). If you create a custom property like this.globalState or this.store and modify it directly, React won't detect those changes, and your component won't re-render to reflect the new state. This will lead to bugs where your UI doesn't match your actual data.
  If you want to separate global vs. local state, a better approach is to structure your this.state with nested objects:

  // In App.js (global state container)
  state = {
    global: {
      user: {},
      appTheme: 'light'
    }
  };
  
  // In Home.js (local state)
  state = {
    local: {
      formInputs: {},
      isModalOpen: false
    }
  };
  

• For function components (using useState hooks): Naming is completely flexible
  If you ever switch to function components, you can name your state variables anything you want. For example:

  // App.js (function component)
  const [globalState, setGlobalState] = useState({ user: {}, appTheme: 'light' });
  
  // Home.js (function component)
  const [localState, setLocalState] = useState({ formInputs: {}, isModalOpen: false });
  

  React only cares that you use the setter function (like setGlobalState) to update the state— the variable names are entirely up to you.

内容的提问来源于stack exchange，提问作者Alim Bolar