In SAS, there are primarily two types of loops that are commonly used:
1. Do loop: The do loop is used to repeat a block of SAS statements a certain number of times. The number of times that the loop executes is determined by a loop index variable, which is usually initialized before the loop begins and incremented or decremented after each iteration of the loop.
Syntax:
do index_variable = start_value to end_value by increment_value;
/* SAS statements */
end;
Examples:
data test;
do i = 1 to 5;
x = i*2;
output;
end;
run;
2. Do while loop: The do while loop is used to repeat a block of SAS statements while a certain condition is true. The condition is typically based on a logical expression, and the loop continues to execute as long as the condition is true.
Syntax:
do while (logical_expression);
/* SAS statements */
end;
Example:
data test;
x = 0;
do while (x < 10);
x + 1;
output;
end;
Run;
These are the two main types of loops in SAS, and they are similar to the loops found in many other programming languages. The specific syntax and behavior of each loop may vary depending on the SAS version being used.
