Sybase InfoMaker 11.5, CD, Win, ENG Especificaciones Pagina 647

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CHAPTER 23 Operators and Expressions
Users Guide 625
Operator precedence in InfoMaker expressions
To ensure predictable results, operators in InfoMaker expressions are evaluated
in a specific order of precedence. When operators have the same precedence,
they are evaluated from left to right.
The following table lists the operators in descending order of precedence:
Table 23-12: Operator precedence in InfoMaker expressions
Overriding the
precedence order
Since expressions in parentheses are evaluated first, to override the precedence
order, enclose expressions in parentheses. You can also use parentheses to
clarify the order of evaluation. Within each set of parentheses, precedence
order applies.
In the expression
x+y*a+b, y is first multiplied by a (because multiplication
has a higher precedence than addition). The result of the multiplication is then
added to
x and this result is then added to b (because the + operators are
evaluated left to right).
To force evaluation in a different order, group expressions with parentheses.
For example, in the expression
x+(y*(a+b)), a+b is evaluated first. The sum
a+b is then multiplied by y, and this product is added to x.
Operator Purpose
( ) Grouping
^ Exponentiation
*, / Multiplication and division
+, - Addition and subtraction; string concatenation
IN,LIKE,BETWEEN SQL SELECT statement conditions
=, >, <, <=, >=, <> Relational operators
AND,OR Logical and and logical or
NOT Logical negation
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