反应无法设置未定义道具的属性

Question

I have a simple component like this

import { Component } from 'react'

export default class SearchList extends Component(){
    constructor(props){
        super(props);
    }
    render(){
        const { placeholder } = this.props;
        return(
            <div className="searchList">
                <input type="text" placeholder={placeholder}/>
                <button>Search</button>
            </div>
        )
    }
}

The somewhere I do <SearchList placeholder="Search Area" />

Why I got error of cannot set property of props of undefined?

Answer 1

When you write a react component extending React.Component you don't need the extra () after React.Component

Use this

export default class SearchList extends Component{
    constructor(props){
        super(props);
    }
    render(){
        const { placeholder } = this.props;
        return(
            <div className="searchList">
                <input type="text" placeholder={placeholder}/>
                <button>Search</button>
            </div>
        )
    }
}