During the compilation
phase, the program data vector is created. The program data vector
includes the two automatic variables _N_ and _ERROR_. The descriptor
portion of the new SAS data set is created at the end of the compilation
phase. The descriptor portion includes the name of the data set, the
number of observations and variables, and the names and attributes
of the variables. Observations are not written until the execution
phase.
Correct answer: a
Syntax checking can
detect many common errors, but it cannot verify the values of variables
or the correctness of formats.
Correct answer: c
The DATA step executes
once for each record in the input file, unless otherwise directed.
Correct answer: d
The remaining variables
are initialized to missing. Missing numeric values are represented
by periods, and missing character values are represented by blanks.
Correct answer: b
The default value of
_ERROR_ is 0, which means there is no data error. When an error occurs,
whether one error or multiple errors, the value is set to 1.
Correct answer: d
By default, at the end
of the DATA step, the values in the program data vector are written
to the data set as an observation. Then, control returns to the top
of the DATA step, the value of the automatic variable _N_ is incremented
by one, and the values of variables that were created in programming
statements are reset to missing. The automatic variable _ERROR_ is
reset to 0 if necessary.
Correct answer: a
The order in which variables
are defined in the DATA step determines the order in which the variables
are stored in the data set.
Correct answer: c
When SAS cannot detect
syntax errors, the DATA step compiles, but it does not execute.
Correct answer: d
The variable type for
Bonus is incorrect. When there is an incorrect variable type, SAS
attempts to automatically convert to the correct variable type. If
it cannot, SAS continues processing and produces output with missing
values.
Correct answer: c
The FREQ procedure detects
invalid character and numeric values by looking at distinct values.
You can use PROC FREQ to identify any variables that were not given
an expected value.
Correct answer: d
At the bottom of the
DATA step, the compilation phase is complete, and the descriptor portion
of the new SAS data set is created. There are no observations because
the DATA step has not yet executed.