使用es6中已计算状态的状态为null的错误

Question

I have this in my jsx

<tr>
{!isEmpty(content) && content.map(o => {

                    if(o.sortKey){ console.log(this.state[`order${o.sortKey}`]) }
})}
</tr>

I couldn't run the app, When I commented the console.log line and do this instead console.log(this.state); console.log(o.sortKey) console.log(this.state); console.log(o.sortKey) , I have {ordercreated_at:'asc'} and created_at but why my computed state has null error?

Answer 1

while calling map method you must return something.

content.map (o => { return (<span></span>)})

here in map method return something and error will go away.