In programming and computer science, semantics refers to the meaning or interpretation of a programming language construct or a piece of code. It defines what the code does and how it behaves, rather than its syntax (which defines how the code is written).
Semantics is concerned with the effect that a piece of code has when executed. It includes aspects such as the manipulation of data, control flow, and interactions with the environment (e.g., input/output operations). Semantics also encompasses concepts such as variable scope, data types, and the behavior of operators and functions.
Understanding the semantics of a programming language is essential for writing correct and efficient code. It helps developers reason about the behavior of their programs and predict how they will behave under different conditions.
Example (Semantics in JavaScript):
In JavaScript, the semantics of the + operator depends on the types of the operands. For example:
- When used with numbers, it performs addition:
2 + 3evaluates to5. - When used with strings, it performs concatenation:
'Hello' + 'World'evaluates to'HelloWorld'.