add key value at the start object js code example

Example 1: add a value to the start of a list python

>>>var=7
>>>array = [1,2,3,4,5,6]
>>>array.insert(0,var)
>>>array
[7, 1, 2, 3, 4, 5, 6]

Example 2: how to get the value in a tag in react

import React, { Component } from 'react';
 
class App extends Component {
  constructor(props) {
    super(props);
    this.handleClick = this.handleClick.bind(this);
  }
 
  handleClick = (event) => {
      alert(event.target.innerText);    // Click Me
      alert(event.target.tagName);      // BUTTON
  }
 
  render() {
    return (
      

        

          
            Click Me
          
        
      
    );
  }
}
 
export default App;