how to name classes in CSS of table

Question

what does this mean

table.my tr{
border-top: 2px solid black;
}

mean in CSS classes. How to manipulate them? Can we give simple name like

my{
border-top{
border-top: 2px solid black;
}

in tr tag of html table

Answer 1

The table.my tr css selector means "all tr tag inside a table tag with a classe my ". You can see all selector here: https://www.w3schools.com/cssref/css_selectors.asp

If you want to only use the my selector, you will need to give the my class to each tr tag in your html file.