I saw a video about it, its example code is here. The result is "Before delete obj.age there are three attributes(age name color) in the obj, After delete obj.age there are two attributes(name color) in the obj" in the video. But when I try it on my computer (macOS 10.15.7 Catalina Chrome 97.0.4692.71), Whether before or after, the console.log results are same ---here are two attributes(name color) in the obj

var obj = {};
obj.name = 'canoe';
obj.age = 1;
obj['color'] = 'blue';
console.log(obj.age);
//before delete age
console.log(obj);
delete obj.age;
//After delete age
console.log(obj);

The result in my computer is:

1
{
  "name": "canoe",
  "color": "blue"
}
{
  "name": "canoe",
  "color": "blue"
}