topic Re: index function in SAS Programming

index function

GN0001 — Tue, 29 Mar 2022 22:55:31 GMT

Hello team

why q is equal to 0.

b = 'x=y' trim(b) will be same, b doesn't have spaces that trim b takes that out!!

data _null_;
length a b $14;
a='ABC.DEF (X=Y) ';
b='X=Y';
q=index(a, b);
w=index(a, trim(b));
put q= w=;
run;
q=0 and w=10 /*log shows it*/

thanks for the response. b&b

Re: index function

Tom — Wed, 30 Mar 2022 00:09:51 GMT

SAS uses FIXED LENGTH character variables.

You defined B to hold 14 bytes. You assigned a value that was only 3 bytes long, so the other 11 bytes were filled with spaces.

Re: index function

ChrisNZ — Wed, 30 Mar 2022 06:23:49 GMT

> b doesn't have spaces that trim b takes that out

Yes it does. Remove the LENGTH statement and it won't.

Re: index function

Kurt_Bremser — Wed, 30 Mar 2022 06:44:08 GMT

@GN0001 wrote:

trim(b) will be same, b doesn't have spaces

b DOES have spaces, because you defined it with a length of 14, so the remaining bytes have to be padded with blanks.

If you do not include b in the LENGTH statement, then the data step compiler will use the length of the assigned literal string to define the length of the variable.

Re: index function

ballardw — Wed, 30 Mar 2022 14:56:42 GMT

Here is code that will demonstrate, in one way, the actual value of B for the first call to index.

data _null_;
length a b $14;
a='ABC.DEF (X=Y) ';
b='X=Y';
z= quote(b);
put z=;
run;

Read the LOG and you will see that the variable Z has a bunch of blanks before the final quote. Which means those blanks are there unless removed.

Re: index function

GN0001 — Mon, 11 Apr 2022 02:38:53 GMT

Hello,

I thought index function finds the position of first character of second string in the first string. As soon as it find it, it returns the position. I didn't know that it checks all the second string in the first string, then it returns the first character position.

Thanks

blue & blue

Re: index function

SASKiwi — Mon, 11 Apr 2022 07:00:25 GMT

I thought index function finds the position of first character of second string in the first string. As soon as it find it, it returns the position

INDEX Function

Searches a character expression for a string of characters, and returns the position of the string's first character for the first occurrence of the string.

If you read the description of the INDEX function as copied from the documentation then it should be clear how it works - it is trying to find the whole of the second string in the first one.

Re: index function

Kurt_Bremser — Mon, 11 Apr 2022 07:56:36 GMT

See Maxim 46 and always keep its consequences in mind.