Question

What are the important syntactic and semantic rules of a programming language?

Answer 1

As the other answers suggest, the syntax of a programming languages specifies which expressions are and are not well-formed in the language.

Semantics is bit more complicated. The meanings of well-formed expressions in a programming language are found in their ability to executed by a computer, i.e., theirexecutability relative to the particular machine instructions (e.g., in the arithmetic-logic unit or ALU of the hardware) ‘hard-wired’ into the circuitry of the computer.

Simply put, as in any language, the syntax of the (programming) language sets the rules for the formal structure of expressions in the language. Also, as in any language, the semantics of the (programming) language determines how those well-formed expressions model the world beyond the language itself.

For all of our ordinary (aka ‘natural’) languages, that outer world is the cosmos and all it contains, including us. For the computer, the ‘world’ modeled by its formal languages (C, Perl, Java, etc.) is the integrated circuity connecting it to the GUI/UX interfaces and other peripheral devices attached to the computer.

Answer 2

Answer:

Semantics is the study of meaning. There are two types of meaning: conceptual meaning and associative meaning. ... The conceptual meaning of concise is expressed in few words, but concise being a good thing is part of the associative meaning