IF

  IF CONDITION VARIABLE=EXPRESSION.
or
  IF CONDITION vector(INDEX)=EXPRESSION.

The IF transformation evaluates a test expression and, if it is true, assigns the value of a target expression to a target variable.

Specify a boolean-valued test expression to be tested following the IF keyword. The test expression is evaluated for each case:

• If it is true, then the target expression is evaluated and assigned to the specified variable.

• If it is false or missing, nothing is done.

Numeric and string variables may be assigned. When a string expression's width differs from the target variable's width, the string result is truncated or padded with spaces on the right as necessary. The expression and variable types must match.

The target variable may be specified as an element of a vector. In this case, a vector index expression must be specified in parentheses following the vector name. The index expression must evaluate to a numeric value that, after rounding down to the nearest integer, is a valid index for the named vector.

Using IF to assign to a variable specified on LEAVE resets the variable's left state. Therefore, use LEAVE after IF, not before.

When IF follows TEMPORARY, the LAG function may not be used.