There are four types of operators:
Arithmetic
Comparison
Boolean
Conversion
Arithmetic
Arithmetic operators operate on integer constants, integer variables, and integer expressions.
Comparison
Binary comparison operators compare two integer operands or two strings. The result of a comparison operation is zero if the condition is false; it is nonzero if the condition is true.
The unary comparison operator (?) checks for the existence of a member in a variable group.
An entire expression is evaluated even if it is found to be false before the evaluation is completed.
Boolean
Boolean operators perform the following logical operations:
Logical AND (&)
Logical OR (│)
Unary logical NOT (!)
The result of a Boolean operation is zero if the result is false and is nonzero if the result is true.
Conversion
The following conversions are allowed:
The unary uppercase operator, ^, converts the lowercase letters “a” through “z” in its string operand to their uppercase equivalents.
The # operator converts a string operand to an integer.
Integer operands within quotation marks (“ ”) are converted to strings.
Supported AMS Operators
Table 5–1 lists the operators supported by AMS.
Table 15. Supported AMS Operators
| Operator | Action |
|---|---|
| – | Unary negation |
| + | Unary positive |
| ! | Unary logical NOT |
| ? | Tests for the existence of a member in a variable group |
| # | Converts a string operand to an integer operand |
| ^ | Converts the lowercase letters in a string operand to uppercase equivalents |
| * | Multiplication |
| / | Integer division |
| % | Integer remainder |
| + | Addition |
| – | Subtraction |
| < | Less than |
| > | Greater than |
| <= | Less than or equal to |
| >= | Greater than or equal to |
| = | Equal to |
| != | Not equal to |
| & | Logical AND |
| | | Logical OR |
Rules for Using Comparison Operators
The following rules apply when using comparison operators in strings:
Masking is not allowed in fixed string constants.
Strings must be in the same case in order to match. Use the ^ operator to change the case, if necessary.
Leading and trailing spaces are included in string comparisons. For example ”AB” does not match “ AB ”.
Precedence of Operators
Table 5–2 shows the precedence of operators. The list is in sequence of highest to lowest precedence. Where several operators are grouped, they are treated without precedence and evaluated from left to right. To change the order of precedence, enclose operands and operators within parentheses [( )].
Table 16. Precedence of Operators
| Evaluation Sequence | Operators |
|---|---|
| First | — (unary) + (unary) ! ? # ^ |
| Second | * / % |
| Third | + (binary) ─ (binary) |
| Fourth | < > <= >= |
| Fifth | = != |
| Sixth | & |
| Last | │ |
Example
The following example shows an expression that adds one to the value of the member named by _TOKEN3 of the variable group UserErrors:
UserErrors:_TOKEN3 + 1