nthlastchildn

nthlastchildn is not a standard selector name in CSS or HTML. It likely refers to the concept of selecting elements by their position from the end of their parent’s list of children, best represented by the CSS pseudo-class :nth-last-child(n). The term as such does not appear in official specifications, but understanding it helps interpret how :nth-last-child(n) works.

The :nth-last-child() pseudo-class matches an element based on its order among the element children of its parent, counting from the end. The argument can be a keyword like odd or even, or a formula in the form an+b, where a and b are integers. The same pattern syntax used for :nth-child() applies here, with counting starting from the last child. For example, ul li:nth-last-child(1) selects the last list item, and ul li:nth-last-child(2) selects the second-to-last item. A pattern like ul li:nth-last-child(3n) selects every third element when counting from the end.

Notes and usage:

- The counting considers only element siblings, not text nodes or comments.

- The selector can be combined with other selectors and combinators, such as ul > li:nth-last-child(2).

- Browser support for :nth-last-child() is widespread in modern engines (Chrome, Firefox, Edge, Safari). Very old browsers may not support it.

In practice, nth-last-child is a powerful tool for styling items relative to the end of a list, such as highlighting the last few items or applying alternating styles from the end. If you encountered “nthlastchildn,” it is most likely a shorthand reference to this function or a misnomer for :nth-last-child(n).