subrange types: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: subrange types

New		Line
1	+	Back to [[Data type\|data types]].
2	+
3	+	Range of values: Corresponds to the definition defined by yourself
4	+
5	+	Storage requirements: Corresponds to the underlying basic data type
6	+
7	+	A subrange type:
8	+
9	+	- is a subrange of a basic data type;
10	+	- can only include values from the range of values that were defined when it was defined;
11	+
12	+	Assigning other values leads to compiler error messages when the program is compiled and the compilation process is aborted. That is, the executable program is not created.
13	+
14	+	There are two ways to define subrange types.
15	+
16	+	Variant 1:
17	+
18	+	``` pascal
19	+	var
20	+	// Defines an integer subrange type
21	+	// in the range of 10 to 123
22	+	tbNumber1 : 10 .. 123;
23	+
24	+	// Defines a character subrange type
25	+	// in the range of A to Z (all uppercase)
26	+	tbLetter1 : 'A' .. 'Z';
27	+	```
28	+
29	+	Variant 2:
30	+
31	+	``` pascal
32	+	Type
33	+	// Defines an integer subrange type
34	+	// in the range of 10 to 123
35	+	TNumber2 = 10 .. 123;
36	+
37	+	// Defines a character subrange type
38	+	// in the range of A to Z (all uppercase)
39	+	TLetter2 = 'A' .. 'Z';
40	+
41	+	var
42	+	tbNumber2 : TNumber2 ;
43	+	tbLetter2 : TLetter2 ;
44	+	```
45	+
46	+	Examples of assigning valid values:
47	+
48	+	``` pascal
49	+	tbNumber1 := 10;
50	+	tbNumber1 := 123;
51	+	tbNumber2 := 10;
52	+	tbNumber2 := 123;
53	+	tbLetter1 := 'F';
54	+	tbLetter2 := 'F';
55	+	```
56	+
57	+	Examples of assigning invalid values:
58	+
59	+	``` pascal
60	+	// the values are outside the subrange
61	+	tbNumber1 := 9;
62	+	tbNumber2 := 124;
63	+	tbLetter1 := 'f';
64	+	tbLetter2 := 'f';
65	+	// the values are string literals
66	+	tbNumber1 := '10';
67	+	tbNumber1 := '123';
68	+	tbNumber2 := '10';
69	+	tbNumber2 := '123';
70	+	```
71	+
72	+	---
73	+	From the Free Pascal wiki, page "subrange types", as it stood on 2020-03-01 after a change by Trev, 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](/wiki-contact).

Back to history