Constants in D Programming Language

Based on the input provided, the target language is Python. Here is the translated code example in Python along with the explanation in Markdown format suitable for Hugo:

Constants are immutable values that are declared at compile time and used throughout a program. In Python, we typically use variables to define constants, but by convention, constants are named in all uppercase letters.

import math

# Constants
S = "constant"

def main():
    print(S)

    # Constant
    N = 500000000
    D = 3e20 / N
    print(D)

    # Explicit type conversion
    print(int(D))

    # Using math.sin, which expects a float
    print(math.sin(N))

if __name__ == "__main__":
    main()

Explanation:

1. Constant Declaration: In Python, we use regular variables to declare constants, but by convention, their names are in uppercase letters to signify that their values should not change.

2. Printing Constants: The print function is used to output the value of the constant S.

3. Arithmetic with Constants: Constants can be used in arithmetic operations. Here, D is computed with arbitrary precision.

4. Type Conversion: In Python, type conversion can be done explicitly using functions like int().

5. Function Calls with Typed Parameters: Some functions, such as math.sin(), require arguments of a specific type (float in this case). Python will handle the conversion as needed.

To run the program, put the code in a file called constants.py and use the Python interpreter to execute it.

$ python constants.py
constant
6e+11
600000000000
-0.28470407323754404

Next example: For.

Feel free to copy and paste the Python code into your Python interpreter or script file to run it.