Depends on what your interpretation of 'law' is, but here in NZ we use the word interchangeably with Act.
So, for example the NZ Crimes Act contains numerous sections which outline the offence and the associated maximum penalty.
For example, section 196 states "everyone is liable to imprisonment for a term not exceeding 1 year who assaults any other person."
Section 2 is the interpretations, which breaks down the terminology of the above offence e.g. outlines what constitutes an assault, because the term is often used incorrectly.
Section 196 is very, very short. A single line. And to commit an offence against section 196 is to commit an offence against the Act.
The entire Act is 131 pages, because it covers a lot of offences the Police deal with. You cant break down ~400 offences to a single page, and most sections are no more than a paragraph.
Also remember that the more ambiguous the law (single sentences allow for greater ambiguity), the more case law is needed to define it. If 'assault' wasn't defined, that would create issues for court rooms. I cant even begin to tell you how many times we got called to assaults that were no more than arguments. The people would say "that's verbal assault". No, no it isn't.