SAS | COMPRESS Function with Examples

COMPRESS function is basically used to compress/removes all the spaces/blanks in a character string. In other words, it removes leading, between and trailing spaces from the strings. The COMPRESS function allows null arguments. A null argument is treated as a string that features a length of zero. Example:

Input: " Geeks For Geeks "
Output: "Geeksforgeeks"

Input: null
Output: null

Syntax:

COMPRESS(String, characters to be removed, Modifier)

Program:

• Sample dataset: SQL

  Data char;
  Input Name $ 1-50 ;
  Cards;
  Geeks   for Geeks
  GeeksforGeeks
  Ge   eks for  Geeks
  Geeks f   or  Geeks
  ;
  Run;
  

  Sample Data Output:
• Using COMPRESS function on sample data defined above: SQL

  Data char1;
  Set char;
  char1 = compress(Name);
  run;
  

  Output
• Remove specific characters In SAS, the additional parameter referred to as MODIFIER was added to the function. The following keywords can be used as modifiers-
  • a – Remove all upper and lower case characters from String.
  • ak - Keep only alphabets from String.
  • kd - Keeps only numeric values
  • d – Remove numerical values from String.
  • i – Remove specified characters both upper and lower case from String.
  • k – keeps the specified characters in the string instead of removing them.
  • l – Remove lowercase characters from String.
  • p – Remove Punctuation characters from String.
  • s – Remove spaces from String. This is default.
  • u – Remove uppercase characters from String.
  Examples:
  • Example 1: Compressing Lowercase Letters SQL

    data _null_;
       x='456-123-852 A 123-8910 c';
       y=compress(x, 'ABCD', 'l');
       put string=;
    run;
    

    Output

    string= 456-123-852 123-8910

  • Example 2: Compressing Space Characters SQL

    data one;
       x='1 9 3 4 5 6 8';
       y=compress(x,, 's');
       put string=;
    run;
    

    Output

    string= 1934568

  • Example 3: Keeping Characters in the List SQL

    data one;
       x='Chemistry A Maths B Physics C';
       y=compress(x, 'ABCD', 'k');
       put string=;
    run;
    

    Output

    string= ABC

  • Example 4: Compressing a String and Returning a Length of 0 SQL

    data _null_;
       x='';
       len=lengthn(compress(x));
       put len=;
    run;
    

    Output

    len= 0