Result Size: 300 x 150
x
 
<!DOCTYPE html>
<html lang='uk'>
<body>
<p>Змінити значення масиву об’єкта.</p>
<p id="demo"></p>
<script>
let x = "";
const myObj = {
  "name":"John",
  "age":30,
  "cars":[ "Ford", "BMW", "Fiat" ]
};
myObj.cars[1] = "Mercedes";
for (let i in myObj.cars) {
  x += myObj.cars[i] + "<br>";
}
document.getElementById("demo").innerHTML = x;
</script>
</body>
</html>