Why if/else is buggy in React?

Question

JavaScript

I'm learning React by tutorial. With the help of it, the following code was lined up:

const myNews = [{
        id: 1,
        author: 'Новость 1',
        text: 'В четверг, четвертого числа...'
    },
    {
        id: 2,
        author: 'Новость 2',
        text: 'Считаю, что $ должен стоить 35 рублей!'
    },
    {
        id: 3,
        author: 'Новость 3',
        text: 'Прошло 2 года с прошлых учебников, а $ так и не стоит 35'
    },
    {
        id: 4,
        author: 'Новость 4',
        text: 'Бесплатно. Без смс, про реакт, заходи'
    },
];


class News extends React.Component {
    render() {

        const {
            novyna
        } = this.props
        let newsTemplate

        if (novyna.lenght) {
            newsTemplate = novyna.map(function(item) {
                return ( <
                    div key = {
                        item.id
                    } >
                    <
                    p className = "news__author" > {
                        item.author
                    }: < /p> <
                    p className = "news__text" > {
                        item.text
                    } < /p><hr/ >
                    <
                    /div>
                )
            })
        } else {
            newsTemplate = < p > Нет < /p>
        }


        return ( <
            div className = "news" > {
                newsTemplate
            } <
            strong > Всего новостей: {
                novyna.length
            } < /strong> <
            /div>
        )

    }
}


const Comments = () => {
    return <p > Нет новостей, нечего комментировать < /p>
}


const App = () => {
        return ( < React.Fragment >
            <
            News novyna = {
                myNews
            }
            /> <
            Comments / >
            <
            /React.Fragment>)
        }



        ReactDOM.render( <
            App / > ,

            document.getElementById('root')
        );

So in this case, if(novyna.lenght) in the conditions triggers the option when there is no news, although the count of the number works correctly.
Also, in the course of experiments, it was found that if you write any garbage in the condition at all, such as if (novyna.lenght=55), then the news is displayed as if nothing had happened.
Why is this and where is my mistake?

Answer 1

So in this case, if(novyna.leng ht ) in the conditions triggers the option when there is no news, although the count of the number works correctly.
www.google.ru/search?q=length

Answer 2

Always put the condition in return, because you just kill the component if God forbid the condition returns null or undefined