how to add class conditionally in react code example

Example 1: react conditional classname

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

Example 2: react add class conditionally

<div className={`btn-group pull-right ${this.props.showBulkActions ? 'shown' : 'hidden'}`}>

Example 3: react conditional class

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

Example 4: conditional classname prop react

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