If I set width:100px for some element, is it contain padding, border and margin?

Answer 1

No.The width will be excluding padding,margin,border.To include padding and margin in specified width you can use :
box-sizing:border-box

Answer 2

There is no padding border or margin if you dont set it ok its only have width

Answer 3

No, it won't contain!! You have to add others property separately!!
https://code.sololearn.com/WrNb7AJaV97y/?ref=app

Answer 4

Actually, it depends on the user agent stylesheet (browser defaults).

https://stackoverflow.com/questions/4698054/css-does-the-width-include-the-padding/4698091

Further reading:

https://www.w3schools.com/css/css3_box-sizing.asp

Answer 5

Only width would be defined by that if I do recall.

Answer 6

Gab