What is so special about constants in Go?

Constants in Go are special for several reasons, primarily due to their role in enhancing code readability, maintainability, and performance. Here's a detailed look at what makes constants in Go particularly noteworthy:

1. Immutability

Constants in Go, once defined, cannot be changed. This immutability is crucial because it ensures that values remain consistent throughout the program's execution. This consistency is vital in situations where a fixed value, such as a mathematical constant like Pi, is used across various parts of an application. By preventing any modifications to the constant values, Go ensures that the integrity of these values is maintained, reducing bugs related to value changes[1][7][9].

2. Compile-Time Evaluation

Constants in Go are evaluated at compile time, not at runtime[9][10]. This means that using constants can lead to performance optimizations since values are computed before the program runs, rather than during execution. This compile-time evaluation contributes to faster execution times and reduced runtime overhead, as the values are directly embedded into the executable code[9][10].

3. Typed and Untyped Constants

Go supports both typed and untyped constants, providing flexibility in how constants are defined and used[1][9][15]. Typed constants are explicitly declared with a specific type and must be used in a manner consistent with that type. Untyped constants, however, do not initially have a specific type and can adapt to different types based on the context in which they are used. This flexibility allows for more generic programming patterns and can help reduce the need for type conversions[1][9][15].

4. High-Precision Calculations

Untyped constants in Go can hold values with arbitrary precision[10][15]. This is particularly useful for mathematical calculations that require a high degree of accuracy. For example, an untyped constant can store the value of Pi with many decimal places without losing precision. When these constants are used in expressions, they maintain their precision until the result needs to be assigned to a variable, at which point the precision is adjusted to fit the variable's type[10][15].

5. Simplicity and Safety

Constants in Go contribute to simpler and safer code. By using constants, develo...