JSFiddle - React, Tailwind, and code Playground

HTML

<div id="data1_1"></div>
<div id="data2_1"></div>
<hr>
<div id="data1_2"></div>
<div id="data2_2"></div>
<hr>
<div id="data1_3"></div>
<div id="data2_3_1"></div>
<div id="data2_3_2"></div>
<hr>
<div id="data1_4"></div>
<div id="data2_4_1"></div>
<div id="data2_4_2"></div>
<hr>

JavaScript

const data1_1 = {
  message: 'Hello',
  obj: {
     message: 'World',
  }
};
const data2_1 = data1_1;
document.getElementById('data1_1').innerHTML = data1_1.message + data1_1.obj.message;
document.getElementById('data2_1').innerHTML = data2_1.message + data2_1.obj.message;
///////////////////////////////////
const data1_2 = {
  message: 'Hello',
  obj: {
     message: 'World',
  }
};
const data2_2 = data1_2;
data2_2.message = 'Zhopa';
document.getElementById('data1_2').innerHTML = data1_2.message + data1_2.obj.message;
document.getElementById('data2_2').innerHTML = data2_2.message + data2_2.obj.message;
///////////////////////////////////
const data1_3 = {
  message: 'Hello',
  obj: {
     message: 'World',
  }
};
const data2_3 = Object.assign({}, data1_3);
data2_3.message = 'Zhopa';
data2_3.obj.message = 'Zhopa';
document.getElementById('data1_3').innerHTML = data1_3.message + data1_3.obj.message;
document.getElementById('data2_3_1').innerHTML = data2_3.message + data2_3.obj.message;
///////////////////////////////////
const data1_4 = {
  message: 'Hello',
  obj: {
     message: 'World',
  }
};
const data2_4 = JSON.parse(JSON.stringify(data1_4));
data2_4.message = 'Zhopa';
data2_4.obj.message = 'Zhopa';
document.getElementById('data1_4').innerHTML = data1_4.message + data1_4.obj.message;
document.getElementById('data2_4_1').innerHTML = data2_4.message + data2_4.obj.message;
///////////////////////////////////