Prior to SAS 9.0, in order to concatenate text strings in SAS, a combination of the TRIM and LEFT functions and the concatenation operator (||) had to be used. A separator, if desired, would have to be added using a quoted string.

Beginning in SAS 9.0, the CAT family of functions was introduced. These functions simplify concatenating text strings by automatically using certain combinations of these functions and the concatenation operator. The new functions are listed below.

    CAT:   concatenates character strings without removing leading or trailing blanks
    CATS:  concatenates character strings and removes leading and trailing blanks
    CATT:  concatenates characters strings and removes trailing blanks
    CATX:  concatenates character strings, removes leading and trailing blanks, and inserts separators

The table below shows a comparison of each CAT function to using the concatenation operator.

    Function		Equivalent Code
    CAT(OF X1-X4)	X1||X2||X3||X4
    CATS(OF X1-X4)	TRIM(LEFT(X1))||TRIM(LEFT(X2))||TRIM(LEFT(X3))||
                         TRIM(LEFT(X4))
    CATT(OF X1-X4)	TRIM(X1)||TRIM(X2)||TRIM(X3)||TRIM(X4)
    CATX(SP, OF X1-X4)	TRIM(LEFT(X1))||SP||TRIM(LEFT(X2))||SP||
                         TRIM(LEFT(X3))||SP||TRIM(LEFT(X4))

There are several differences in the CAT family of functions compared to the concatenation operator for concatenating character strings. If a variable has not been previously assigned a length, the variable created with the CAT function assigns a length of 200. Using the concatenation operator, the length assigned is the sum of the lengths of the values being concatenated. Another difference is in how missing values are treated. When using the CATX function with a separator, missing values are ignored. When using the concatenation operator and defining a separator, if any variable has a missing value, multiple separators appear consecutively.

Sample code is included on the Full Code tab.

For more information about concatenation in SAS, see the following SAS tutorial video:
 

Operating System and Release Information

Product Family	Product	System	Product Release		SAS Release
			Reported	Fixed*	Reported	Fixed*
SAS System	Base SAS	z/OS	9.21		9.2 TS2M3
		Microsoft® Windows® for 64-Bit Itanium-based Systems	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 Datacenter 64-bit Edition	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 Enterprise 64-bit Edition	9.21		9.2 TS2M3
		Microsoft Windows XP 64-bit Edition	9.21		9.2 TS2M3
		Microsoft® Windows® for x64	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 Datacenter Edition	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 Enterprise Edition	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 Standard Edition	9.21		9.2 TS2M3
		Microsoft Windows Server 2003 for x64	9.21		9.2 TS2M3
		Microsoft Windows Server 2008	9.21		9.2 TS2M3
		Microsoft Windows Server 2008 for x64	9.21		9.2 TS2M3
		Microsoft Windows XP Professional	9.21		9.2 TS2M3
		Windows 7 Enterprise 32 bit	9.21		9.2 TS2M3
		Windows 7 Enterprise x64	9.21		9.2 TS2M3
		Windows 7 Home Premium 32 bit	9.21		9.2 TS2M3
		Windows 7 Home Premium x64	9.21		9.2 TS2M3
		Windows 7 Professional 32 bit	9.21		9.2 TS2M3
		Windows 7 Professional x64	9.21		9.2 TS2M3
		Windows 7 Ultimate 32 bit	9.21		9.2 TS2M3
		Windows 7 Ultimate x64	9.21		9.2 TS2M3
		Windows Vista	9.21		9.2 TS2M3
		Windows Vista for x64	9.21		9.2 TS2M3
		64-bit Enabled AIX	9.21		9.2 TS2M3
		64-bit Enabled HP-UX	9.21		9.2 TS2M3
		64-bit Enabled Solaris	9.21		9.2 TS2M3
		HP-UX IPF	9.21		9.2 TS2M3
		Linux	9.21		9.2 TS2M3
		Linux for x64	9.21		9.2 TS2M3
		OpenVMS on HP Integrity	9.21		9.2 TS2M3
		Solaris for x64	9.21		9.2 TS2M3

* For software releases that are not yet generally available, the Fixed Release is the software release in which the problem is planned to be fixed.

---

/* Demonstrates each function */
data test;
  input (x1-x4) ($); 
  x5=' 5';
  length new1 $40 new2-new4 $10 ; 
  new1=cat(of x1-x5);
  new2=cats(of x1-x5);
  new3=catt(x1,x2,x3,x4,x5);
  new4=catx(',', of x1-x5);
  keep new:;
datalines;
1 2 3 4
5 6 . 8
;
run;

proc print;
run;

/* Demonstrates the difference in how missing values are handled */
data test;
 x1='1';
 x2=' ';
 x3='6';
 newx=catx(',', of x1-x3);
 newx1=trim(left(x1))||','||trim(left(x2))||','||trim(left(x3));
 put newx=;
 put newx1=;
run;

/* output one */
               new1                   new2      new3       new4

1       2       3       4        5    12345    1234 5    1,2,3,4,5
5       6               8        5    5685     568 5     5,6,8,5

/* output two */
newx=1,6
newx1=1, ,6

The new CAT functions make it easier to concatenate text strings.

Type:	Usage Note
Priority:

Date Modified:	2020-10-06 08:34:44
Date Created:	2012-05-25 13:14:15