TAL Reference Manual

Language Elements

TAL Reference Manual—526371-001

2-5

Constants

A constant is a value you can store in a variable, declare as a LITERAL, or use as part

of an expression. Constants can be numbers or character strings. The kind and size of

constants a variable can accommodate depends on the data type of the variable, as

described in Data Representation on page 3-1. The following examples show

constants:

654 - !Numeric constant

"abc" - !Character string constant

Constant Expressions

A constant expression is an arithmetic expression that contains only constants,

LITERALs, and DEFINEs as operands. You can use a constant expression anywhere a

single constant is allowed. The following examples show constant expressions:

255

8 * 5 + 45 / 2

For more information, see LITERALs and DEFINEs on page 5-1.

Number Bases

You can specify numeric constants in binary, octal, decimal, or hexadecimal base

depending on the data type of the item, as described in Data Representation on

page 3-1. The default number base in TAL is decimal. The following examples show

constants in each number base:

Table 2-4. Identifier Classes

Class Meaning

Block Global Data Block

Code Read-only (P-relative) array

Variable Simple variable, array, simple pointer, structure pointer,

structure, or structure data item

DEFINE Named text

Function Procedure or subprocedure that returns a value

Label Statement Label

LITERAL Named constant

PROC Procedure or subprocedure that does not return a value

Template Template Structure