SAS 9.4 Language Reference, 6th Edition

Definitions for SAS Expressions

expression

is generally a sequence of operands and operators that form a set of instructions that

are performed to produce a resulting value. You use expressions in SAS program

statements to create variables, assign values, calculate new values, transform

variables, and perform conditional processing. SAS expressions can resolve to

numeric values, character values, or Boolean values.

operands

are constants or variables that can be numeric or character.

operators

are symbols that represent a comparison, arithmetic calculation, or logical operation;

a SAS function; or grouping parentheses.

simple expression

is an expression with no more than one operator. A simple expression can consist of

one of the following single operators:

• constant

• variable

• function

compound expression

is an expression that includes several operators. When SAS encounters a compound

expression, it follows rules to determine the order in which to evaluate each part of

the expression.

WHERE expressions

is a type of SAS expression that is used within a WHERE statement or WHERE=

data set option to specify a condition for selecting observations for processing in a

DATA or PROC step. For syntax and further information about WHERE

expressions, see Chapter 11, “WHERE-Expression Processing,” on page 177.

Examples of SAS Expressions

The following are examples of SAS expressions:

• 3

• x

• x+1

• age<100

• trim(last)||', '||first

92 Chapter 6 • Expressions