|Functions and CALL Routines|
|Restriction:||I18N Level 0|
|Length of Returned Variable|
|Length of Returned Variable: Special Cases|
|Example 1: Concatenating Strings That Have No Missing Values|
|Example 2: Concatenating Strings That Have Missing Values|
|CATX(delimiter, item-1 <, ...item-n>)|
specifies a constant, variable, or expression, either character or numeric. If item is numeric, then its value is converted to a character string by using the BESTw. format. In this case, SAS does not write a note to the log. For more information, see The Basics.
The CATX function first copies item-1 to the result, omitting leading and trailing blanks. Then for each subsequent argument item-i, i=2, ..., n, if item-i contains at least one non-blank character, then CATX appends delimiter and item-i to the result, omitting leading and trailing blanks from item-i. CATX does not insert the delimiter at the beginning or end of the result. Blank items do not produce delimiters at the beginning or end of the result, nor do blank items produce multiple consecutive delimiters.
In a DATA step, if the CATX function returns a value to a variable that has not previously been assigned a length, then that variable is given a length of 200 bytes. If the concatenation operator (||) returns a value to a variable that has not previously been assigned a length, then that variable is given a length that is the sum of the lengths of the values which are being concatenated.
If CATX returns a value in a temporary buffer, the length of the buffer depends on the calling environment, and the value in the buffer can be truncated after CATX finishes processing. In this case, SAS does not write a message about the truncation to the log.
The results of the CAT, CATS, CATT, and CATX functions are usually equivalent to results that are produced by certain combinations of the concatenation operator (||) and the TRIM and LEFT functions. However, the default length for the CAT, CATS, CATT, and CATX functions is different from the length that is obtained when you use the concatenation operator. For more information, see Length of Returned Variable.
Using the CAT, CATS, CATT, and CATX functions is faster than using TRIM and LEFT, and you can use them with the OF syntax for variable lists in calling environments that support variable lists.
Note: In the case of variables that have missing values, the concatenation produces different results. See Concatenating Strings That Have Missing Values.The following table shows equivalents of the CAT, CATS, CATT, and CATX functions. The variables X1 through X4 specify character variables, and SP specifies a delimiter, such as a blank or comma.
data _null_; separator='%%$%%'; x='The Olympic '; y=' Arts Festival '; z=' includes works by '; a='Dale Chihuly.'; result=catx(separator,x,y,z,a); put result $char.; run;
----+----1----+----2----+----3----+----4----+----5----+----6----+----7 The Olympic%%$%%Arts Festival%%$%%includes works by%%$%%Dale Chihuly.
The following example shows how the CATX function concatenates strings that contain missing values.
options nodate nostimer ls=78 ps=60; data one; length x1-x4 $1; input x1-x4; datalines; A B C D E . F G H . . J ; run; data two; set one; SP='^'; test1=catx(sp, of x1-x4); test2=trim(left(x1)) || sp || trim(left(x2)) || sp || trim(left(x3)) || sp || trim(left(x4)); run; proc print data=two; run;
SAS creates the following output:
The SAS System 1 Obs x1 x2 x3 x4 SP test1 test2 1 A B C D ^ A^B^C^D A^B^C^D 2 E F G ^ E^F^G E^ ^F^G 3 H J ^ H^J H^ ^ ^J