Constants
Constants are fixed values in programming that cannot be altered during program execution, used to represent immutable data such as mathematical values, configuration settings, or symbolic names. They enhance code readability, maintainability, and safety by preventing accidental modifications, and are supported in most programming languages through specific keywords or conventions. Common examples include numeric constants like PI, string literals, or environment variables.
Developers should use constants to define values that remain unchanged throughout a program, such as mathematical constants (e.g., π), configuration parameters (e.g., API keys), or magic numbers, to improve code clarity and reduce bugs. This is particularly important in large-scale applications, collaborative projects, or when adhering to best practices like DRY (Don't Repeat Yourself) to ensure consistency and ease of updates. In languages like JavaScript (const), Python (constants by convention), or Java (final), constants help enforce immutability and prevent runtime errors.