Operator Precedence
When several operations occur in an expression, each part is evaluated and resolved in a predetermined order called operator precedence. Parentheses can be used to override the order of precedence and force some parts of an expression to be evaluated before other parts. Operations within parentheses are always performed before those outside. Within parentheses, however, normal operator precedence is maintained.
Types of Operators
When expressions contain operators from more than one category, arithmetic operators are evaluated first, comparison operators are evaluated next, and logical operators are evaluated last. Comparison operators all have equal precedence; that is, they are evaluated in the left-to-right order in which they appear.
Table 11-24 List of Operators
| Arithmetic | Comparison | Logical |
|---|---|---|
| Negation (-) | Equality (=) | Not |
| Exponentiation (^) | Inequality (<>) | And |
| Multiplication and division(*,/) | Less than (<) | Or |
| Integer division (\) | Greater than (>) | Xor |
| Modulus arithmetic (Mod) | Less than or equal to (<=) | |
| Addition and subtraction (+, -) | Greater than or equal to (>=) | |
| String concatenation (&) |
When multiplication and division occur together in an expression, each operation is evaluated as it occurs from left to right. Likewise, when addition and subtraction occur together in an expression, each operation is evaluated in order of appearance from left to right.