初學(xué)redux，報(bào)錯(cuò)Cannot read property 'map' of undefined

import React from 'react';
import DifferentLabels from './DifferentLabels'

const DifferentLabelsDiv = ({ todos, toggleTodo }) => (
    <div>
        {todos.map(todo =>
            <DifferentLabels
                key={todo.id}
                {...todo}
            />
        )}
    </div>
)

class DifferentLabelsList extends React.Component {

    render(){
        return (
            <div className={'left_layout'}>
                <div>
                    展示不同標(biāo)簽
                </div>
                <DifferentLabelsDiv />
            </div>
        )
    }
}

export default DifferentLabelsList;

import React from 'react'
import PropTypes from 'prop-types'

const DifferentLabels = ({ onClick, completed, text }) => (
    <div
    >
        {text}
    </div>
);

export default DifferentLabels