title: how to display number when i click on button !it repeats multiple !when i pressed many times like pressing number button in id
body: <p>I am developing code for number pad on-screen! When I click the button for example '7' for multiple times It will display multiple times.</p>
  
  <p>I gave static value in update state method and called through button it's showing only one time</p>
  
  <pre><code>this.state={
      id:''
  }
  
  ChangeTextFunction=()=&gt;{
      this.setState({                
          id:'7'         
      })
  }
  </code></pre>