An expression is a combination of operators and operands. Operands can be constants, items, variables, functions, or some combination thereof. Operators can be
arithmetic (+, -, *, /),
relational (=, <>, >, <, >=, <=) or
logical (
and, or, not). Every expression evaluates to a value and can therefore be used as a sub-expression of other expressions. There are three types of expressions: numeric, string, and logical.
They evaluate to numbers. The following are numeric expressions:
4
4 + 5
(A / B) + 3
A * (B + C/D)
A + sqrt(B)
They evaluate to strings. The following are string expressions:
"Yes"
concat(FIRST_NAME, " ", LAST_NAME)
edit("ZZZZ9", A + B)
Logical expressions (conditions) evaluate to
true (1) or
false (0). The following are logical conditions:
KIDS > 5
SEX = 2 and AGE >= 12