Basic Pascal Tutorial/Chapter 1/Standard Functions

1F - Standard Functions (author: Tao Yue, state: unchanged)

Pascal has several standard mathematical functions that you can utilize. For example, to find the value of sin of pi radians:

value := sin (3.141592653589793238462643383);

Note that the sin function operates on angular measure stated in radians, as do all the trigonometric functions. If everything goes well, value should become 0.

Functions are called by using the function name followed by the argument(s) in parentheses. Standard Pascal functions include:

For ordinal data types (integer or char), where the allowable values have a distinct predecessor and successor, you can use these functions:

Real is not an ordinal data type! That's because it has no distinct successor or predecessor. What is the successor of 56.0? Is it 56.1, 56.01, 56.001, 56.0001?

However, for an integer 56, there is a distinct predecessor — 55 — and a distinct successor — 57.

The same is true of characters:

 'b'
 Successor: 'c'
 Predecessor: 'a'

The above is not an exhaustive list, as modern Pascal compilers include thousands of functions for all sorts of purposes. Check your compiler documentation for more.

From the Free Pascal wiki, page "Basic Pascal Tutorial/Chapter 1/Standard Functions", as it stood on 2022-08-20 after a change by Kai Burghardt, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.