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Arithmetic operators

  • Članak

This article contains examples of how to use the type conversion rules for arithmetic operators. The examples illustrate how the operators should be used and the effect of the type conversion that the AL compiler performs. The examples are divided into groups corresponding to the data types in AL.

Unary arithmetic operators

The unary arithmetic operators in AL are prefix operators with the following syntax.

PrefixExpression = PrefixOperator Expression

The following table shows the data types for which the unary operators in AL are defined, and the resulting data types.

Unary operator Option Integer Decimal
+ integer integer decimal
- integer integer decimal

Binary arithmetic operators

The following table shows the data types for which the binary arithmetic operators are defined. The binary arithmetic operators in AL are all infix operators.

InfixExpression = LeftExpression InfixOperator RightExpression
Operator Boolean Byte Char Option Integer Decimal Date Time Text Code
+ No Yes Yes Yes Yes Yes Yes Yes Yes Yes
- No Yes Yes Yes Yes Yes Yes Yes No No
* No Yes Yes Yes Yes Yes No No No No
/ No Yes Yes Yes Yes Yes No No No No
DIV No Yes Yes Yes Yes Yes No No No No
MOD No Yes Yes Yes Yes Yes No No No No

In the table, Yes means that the operator can take at least one operand (left, right, or both) of the given type; No means that the operator can't be used with the given type.

The following table defines the valid uses of the binary arithmetic operators, and the resulting data types.

Definition of type conversion rules for the + operator

The + operator Boolean Byte/Char Option Integer Decimal Date Time Text Code
Boolean
Byte/Char Integer Integer (C) Integer (C) Decimal (C)
Option Integer Integer (C) Integer (C) Decimal (C)
Integer Integer (C) Integer (C) Integer (C) Decimal (C)
Decimal Decimal (C) Decimal (C) Decimal (C) Decimal (C)
Date Date (A) (C) Date (A) (C) Date (A) (C) Date (A) (C) (D)
Time Time(B) (C) Time(B) (C) Time(B) (C) Time(B) (C) (D)
Text Text Text
Code Text Code

(A) The operation isn't defined for the Date 0D.

(B) The operation isn't defined for the Time 0T.

(C) Overflow might occur.

(D) The operation isn't defined if the Decimal has a fractional part.

Example 1

This table illustrates type conversion in integer operator expressions.

Operator Name Expression Resulting data type
+ Time addition Time + Integer Time
- Time difference Time - Time Integer

The time unit is milliseconds. If time is undefined (0T), a runtime error occurs.

Example 2

This table illustrates type conversion in text and code (String) operator expressions.

Operator Name Expression Resulting data type
+ Concatenation Text + Text Text
+ Concatenation Text + Code Text
+ Concatenation Code + Text Text
+ Concatenation Code + Code Code

See also

AL operators
Boolean operators
Relational operators