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SAS Functions [7-14]

SUBSTR Function

You can extract texts or phrases from a character variable using the SUBSTR function. 

Let's take a look at the PHONELIST data set below. 

The PHONELIST data set above contains a list of phone numbers.

[Reminder: To see the PHONELIST data set on SAS Studio, run the code in the yellow box above]

Now, let's take a look at an example of the SUBSTR function. 

Example

Data PhoneList2;
Set Phonelist;
Ext1 = substr(Tel, 9);
Run;

Note: the 2nd parameter is 9. 

The 2nd parameter tells SAS the position where the extraction begins.

In our example, the extraction begins at the 9th position.

Tel: 780-444-8989

  • 1st: 7
  • 2nd: 8
  • 3rd: 0
  • 4th: -
  • 5th: 4
  • 6th: 4
  • 7th: 4
  • 8th: -
  • 9th: 8
  • 10th: 9
  • 11th: 8
  • 12th: 9

The SUBSTR function will extract the portion of the character value from the 9th position till the end of the character value.

E.g. 780-444-8989 --> 8989

Make sense?

Specify # of characters to extract

You can also specify the number of characters to extract.

Example

Data PhoneList3;
Set Phonelist;
Ext2 = substr(Tel, 9, 2);
Run;

When using the SUBSTR function, you can add a 3rd parameter to tell SAS the # of characters to extract. 

In our example, the third parameter is 2.
Ext2 = substr(Tel, 9, 2);
SAS will start the extraction at the 9th position and read 2 characters.

As a result, only the characters from the 9th and 10th position are extracted, as demonstrated in the image above.

[Tips: play around with the different parameters and you will get more familiar with the SUBSTR function.] 
Exercise

Write a SAS program to extract the area code (first 3 digit) from the variable TEL. 

Create any data set or variables if necessary.
Need some help? 


HINT:
The area code starts at the first position.


SOLUTION:
Data PhoneList4;
Set Phonelist;
Area = substr(Tel, 1, 3);
Run;

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