SAS Index

SAS Day 14: INDEX/INDEXC

Problem: 

We want to select all the MedDRA_PT contains “Acute leukemia”. such as Acute leukemia, Acute leukemia in remission.

Background of INDEX function: 

INDEX function searches a character expression for a string of characters, and it returns the position of the string’s first character for the first occurrence of the string.

While theoretically, we use Index function to return the position of the string, most of the time, we use it to select whether a string exists in the variable.

Example:

data _null_;
a=index("xyz omy ooo","ooo");
put a=;
run; 

a=9

Bru-nO / Pixabay

Solution:

data luk;
set nl;
where  index(meddra_pt,"Acute leukaemia")>0;
run;

Output:

Note: 

The Function INDEXC has the similar application, however, we need to use it with caution, because the order of letters does not matter in INDEXC function. Instead of searching the complete string, “abc” , INDEXC searches all the terms contains “a”, “b”, “c” in any order.

Example:

data _null_;
a=indexc("hiphop dance","ai");
put a=;
b=index("hiphop dance", "ai");
put b=;
run; 

a=2
b=0

Happy SAS Coding! 🤩