Spreadsheet: Operators

MedCalc divides the operators in the following groups:

Arithmetic operators: arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.
Comparison Operators: comparison operators compare two numbers or two strings. The result is a boolean value expressed as a number, either 1 (=TRUE), or 0 (=FALSE).
Unary operators: operators that act upon a single value to produce a new value.
Logical operators: logical operators operate on boolean expressions and values.

Operators in order of precedence

The order of operations can be changed using parentheses. Operations within parentheses are performed first.
The exponentiation operator ^ is left-associative. In the expression 2^3^2, 2^3 is evaluated first. 2^3^2 is (2^3)^2 (=64), not 2^(3^2) (=512).
When arithmetic and comparison operators are combined in one expression, the arithmetic are performed first.
The not operator ! changes a FALSE value into TRUE (=1), and a TRUE value into FALSE (=0). Zero values or empty strings are evaluated to FALSE.
- !0 results in 1
- !1 results in 0
- !5 results in 0
- !"" results in 1 (an empty strings is evaluated to FALSE)
- !"MedCalc" results in 0
MedCalc may drop superfluous unary minus or plus signs (for example -0 is 0, and +3 is 3).

-2^3 returns -8 (the power operator has precedence over the unary minus).
SQRT(9)=3 returns 1 (TRUE).
B6<5+3 returns 1 if the contents of B6 is less than 8, otherwise this expression returns 0.
5+3*(A1>3) returns 8 if cell A1 contains a value greater than 3 (since A1>3 = TRUE = 1). If A1 contains 3 or a number less than 3, this expression returns 5 (A1>3 = FALSE = 0).