title: why when I console.log(event) for `from` onSubmit, I don't see that preventDefault method
body: <p>I am learning React.js.  In the code below I use a form and I am trying to see what that <code>even</code> contains. So I <code>console.log</code> it. But then I noticed in the log I don't have that <code>preventDefault</code> method. So, where is that coming from? why when I log the even it's not there?</p>
  
  <pre><code>    constructor(props) {
          super(props);
          console.log('cons');
          this.onInputchange = this.onInputchange.bind(this);
  
          this.state = { name: 'Dear. ' };
      }
  
      onInputchange(event) {     
          this.setState({ name: event.target.value });
      }
  
      onFormSubmit (event) {
          event.preventDefault();
          console.log(event);
          debugger;  
      }
  
      render() {
          console.log('rende');
          return (
              &lt;form onSubmit={this.onFormSubmit} className="input-group" borderColor='pink'&gt;
                  &lt;input
                      className="form-control"
                      value={this.state.name}
                      onChange={this.onInputchange}
                      placeholder="enter the name please "
                  /&gt;
                  &lt;span className="input-group-btn"&gt;
                      &lt;button type="submit" className="btn btn-secondary"&gt;submit&lt;/button&gt;
                  &lt;/span&gt;
              &lt;/form&gt;
          );
      }
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/mqqD9.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mqqD9.jpg" alt="enter image description here"></a></p>