How to add multiple classes to a ReactJS Component?

Question

I am new to ReactJS and JSX and I am having a little problem with the code below.

I am trying to add multiple classes to the className attribute on eac

Answer 1

Just adding, we can filter out empty strings.

className={[
    'read-more-box',
    this.props.className,
    this.state.isExpanded ? 'open' : 'close',
].filter(x => !!x).join(' ')}