precedence (redirected from precedency)

precedence

The order in which an expression is processed. Mathematical precedence is normally:

1. unary + and - signs
2. exponentiation
3. multiplication and division
4. addition and subtraction

In order to properly compute the formula that converts Fahrenheit to Celsius, which is fahrenheit-32*5/9, the expression

(fahrenheit-32)*5/9

must be used with parentheses separating the fahrenheit-32 from the multiplication. Since multiplication is evaluated before subtraction, 32 would be multiplied by 5 first, which is not what is wanted.

Logical precedence is normally:

1. NOT
2. AND
3. OR

In the dBASE query:

 list for item = "TIE" .and. color = "GRAY"
   .or. color = "RED"

all gray ties and anything red will be selected, since ANDs are evaluated before ORs. Grouping the colors in parentheses as in the example below yields only gray and red ties.

  (color="GRAY" .or. color="RED") 

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precedence - operator precedence