反应不渲染道具，但可以在console.log中看到

Question

in my render, I have this const arr = []

In my return I have this

{
    this.state.rows.map((qc) =>
        qc.BinsByDayByOrchardsQCs.map((qc2) =>
            qc2.BinsByDayByOrchardsQCsDefects.map((qc3) =>
              {!arr.includes(qc3.Defect) && arr.push(qc3.Defect) &&
                (<div className="row table">
                    <div className="column-label bold">{qc3.Defect}</div>
                    {console.log("testing", qc3.Defect)}
                </div>)
              }
            ) 
        )
    )
}

In my console.log I can actually see the 4 results, which is my desired outcome. It looks like this:

testing Scuff
testing Sunburn
testing Bruise
testing Hail damage

Any ideas on why nothing is rendering on the page?

Answer 1

Because you have curly braces {} , you need to either change them to parentheses () or use an explicit return statement:

qc2.BinsByDayByOrchardsQCsDefects.map((qc3) =>
    {!arr.includes(qc3.Defect) && arr.push(qc3.Defect) &&
        (<div className="row table">
            <div className="column-label bold">{qc3.Defect}</div>
            {console.log("testing", qc3.Defect)}
        </div>)
      )
    )