title: Reactjs : TypeError: Cannot read property 'value' of undefined
body: <p>I am new to Reactjs and trying to change the of value text which is entered by user in textbox, after button click event. 
  But after button click event I am getting error "TypeError: Cannot read property 'value' of undefined" at handleChange(e) function.Can anyone please help me with whats going wrong here?? </p>
  
  <p>Here is the component I am working with : </p>
  
  <pre><code> Constructor(props){
      super();
      this.state={
               typedtext: 'Nothing'
             }
        };
  
      handleClick(){
                this.handleChange(this.state.typedtext)
               }
  
      handleChange(e){
              this.setState({ typedtext: e.target.value });  
                }
  
      render(){
  
       return(
  
          &lt;div&gt;
           &lt;label&gt; Typed Value is : {this.state.typedtext} &lt;/label&gt; &lt;p&gt; 
           &lt;/p&gt;
  
          &lt;label&gt; Type Something here &lt;/label&gt;
            &lt;input type='text'onChange={(e)=&gt;this.handleChange(e)} 
                 value=  {this.state.typedtext}/&gt;
  
         &lt;button onClick={()=&gt;this.handleClick()}&gt; Copy Text &lt;/button&gt;
         &lt;/div&gt;
        );
      }
  }
  </code></pre>