Analyzing react className added js

feasible

1.ES6 template string ``

className={`title ${index === this.state.active ? 'active' : ''}`}

2.join composed of a string

className={["title", index === this.state.active?"active":null].join(' ')}

3. rely classnames
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4. Multi-write over the original class

className={index === this.state.active?"active title":"title"}

Infeasible

1. Write a separate className

className="title" className={index === this.state.active?"active":null}