Can multiple different HTML elements have the same ID if they're different elements?

Question

Can multiple HTML elements have the same ID if they\'re of different element types? Is a scenario like this valid? Eg:

div#foo
span#foo
a#foo

Answer 1

No. two elements with the same id are not valid. IDs are unique, if you wish to do something like that, use a class. Don't forget that elements can have multiple classes by using a space as a delimeter: