jsx函数中怎么渲染组件？

import React from 'react'
import Com from './com'

const Text = () => {

    const renderDom = () => {
        return <div>222222</div>
    }

    const renderComDom = () => {
        return <Com/>
    }

    return (
        <div>
            {
                renderDom()
            }
            {
                renderComDom() 
            }
        </div>
    )

}

export default Text

请问下为什么renderDom能正常渲染renderComDom却渲染不出来？