add class conditionally in react code example

Example 1: react conditional classname

<div className={`banner ${active ? "active" : ""}`}>{children}</div>

Example 2: react conditional class

<div className={"btn-group pull-right " + (this.props.showBulkActions ? 'show' : 'hidden')}>

Example 3: conditional classname prop react

<span className={todo.completed ? "true" : ""}>