ts报错：Object is possibly 'null' 请问怎么解决？

Question

这么写是不行的吗？请问应该怎么写呢？

`

readonly state = {
    fold: true,
    answer: null
};

render () {
    return (
        <div>{ this.state.answer && this.state.answer.content }</div>
    )
}
`

Answer 1

readonly state: any = {
    fold: true,
    answer: null
};