使用React.js写一个类似单选框与复选框的功能

单选框
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>Hello React!</title>
    <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
    <style>
        .item{
            width: 20px;
            height: 20px;
            margin: 20px 0;
            border: 1px solid #666;
        }
        .item>div{
            height: 20px;
        }
        .checked{
            background: red;
        }
    </style>
</head>
<body>
    <div id="root"></div>
    <script type="text/babel">
        class CheckBox extends React.Component {
            constructor(props) {
                super(props);
                this.state = {
                    tagIndexList: [],
                    value:[],
                    index:null,
                    arr: [
                        {
                            item: "item1"
                        },
                        {
                            item: "item2"
                        },
                        {
                            item: "item3"
                        },
                        {
                            item: "item4"
                        }
                    ]
                };
                this.handleClick = this.handleClick.bind(this);
            }
            handleClick(num,item){
             this.setState({
                index:num
             })
             console.log(item);
            }
            render() {
                return (
                    <div>
                        {
                            this.state.arr.map((item, index) => {
                                return (
                                    <div key={item.item}  className="item">
                                       <div className={this.state.index===index?"checked":""} onClick={()=>this.handleClick(index,item.item)}></div><span>{item.item}</span>
                                    </div>
                                )
                            })
                        }
                    </div>
                )
            }
        }
        ReactDOM.
                    
                