title: Boolean in React read as undefined
body: <p>I have backend and db isUrgent type as boolean. In React, I have some code for frontend which works perfectly for getting the boolean data to db and backend, but the frontend reads that data as undefined. Why is that? :</p>
  <pre><code> this.state = {
          id: this.props.match.params.id,
          name: '',
          offerCost: ' ',
          isUrgent: ' ',
  </code></pre>
  <p>(...)</p>
  <pre><code>this.changeUrgentHandler = this.changeUrgentHandler.bind(this);
  </code></pre>
  <p>(...)
  componentDidMount(){</p>
  <pre><code>    if(this.state.id === 'add'){
          return
      }else{
          OfferService.getOfferById(this.state.id).then( (res) =&gt;{
              let offer = res.data;
              this.setState({
                  name: offer.name,
                  offerCost: offer.offerCost,
                  isUrgent: offer.isUrgent,
  </code></pre>
  <p>(...)</p>
  <pre><code>saveOrUpdateOffer = (e) =&gt; {
      e.preventDefault();
      let offer = {
          name: this.state.name,
          offerCost: this.state.offerCost,
          isUrgent: this.state.isUrgent,
  </code></pre>
  <p>(...)</p>
  <pre><code>&lt;div className = &quot;form-group&quot;&gt;
  &lt;label&gt; Urgent&lt;/label&gt;
  &lt;input placeholder=&quot;isUrgent&quot; name=&quot;isUrgent&quot; className=&quot;form-control&quot;
  value={this.state.isUrgent} onChange={this.changeUrgentHandler}/&gt;
  &lt;/div&gt;
  </code></pre>