出现tags.map is not a function

代码如下：

import React from 'react'
class NameCard extends React.Component {
    render() {

        const { name,number,isHuman,tags} = this.props
        return (
            <div >
                <h4 >{name}</h4>
                <ul>
                    <li>电话：{number}</li>
                    <li>
                        {isHuman ? '人类' : '外星生物'}
                    </li>
                    <hr />
                    <p>
                        {
                            tags.map((atag,index)=>(<span key={index}>{atag}</span>))
                        }
                    </p>
                </ul>
            </div>
        )
    }
}
export default NameCard

求助为什么会出现这种情况：

报错如下：