Pascal Tutorial 1F - Standard Functions

1F - Standard Functions

Pascal has several standard mathematical functions that you can utilize. For example, to find the value of sin of pi radians,
value := sin (3.1415926535897932);
Note that the sin function operates on angular measure stated in radians. This is true of 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 are:

Function Name	Description	Argument type	Return type
abs	absolute value	real or integer	same as argument type
arctan	arctan in radians	real or integer	real
cos	cosine of a radian measure	real or integer	real
exp	`e` to the given power	real or integer	real
ln	natural logarithm	real or integer	real
round	round to nearest integer	real	integer
sin	sin of a radian measure	real or integer	real
sqr	square (power 2)	real or integer	same as argument type
sqrt	square root (power 1/2)	real or integer	real
trunc	truncate (round down)	real or integer	integer

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

Function	Description	Argument type	Return type
chr	character with given ASCII value	integer	char
ord	ordinal value	integer or char	integer
pred	predecessor	integer or char	same as argument type
succ	successor	integer or char	same as argument type

Real is not an ordinal data type! That's because it has no distinct successor or predecessor. What is the successor of 56.0? It could be
56.1 56.01 56.001 56.0001 56.00001 56.000001

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'