RPG Cafe: Fall 2023: Built-in functions %LEFT and %RIGHT

Content

Fall 2023: Built-in functions %LEFT and %RIGHT

• %LEFT: Return the leftmost characters in a string
• %RIGHT: Return the rightmost characters in a string

Details

%LEFT

Built-in function %LEFT(parameter_name) returns the leftmost characters in a string.

          dcl-s string char(10) inz('abcdefghij');
          dcl-s string2 varchar(10);

          string2 = %LEFT(string : 3);
          // string2 = "abc"

%RIGHT

Built-in function %RIGHT(parameter_name) returns the rightmost characters in a string.

          dcl-s string char(10) inz('abcdefghij');
          dcl-s string2 varchar(10);

          string2 = %RIGHT(string : 3);
          // string2 = "hij"

Using %LEFT and %RIGHT where characters have different sizes, such as for UTF-8 data.

When the data can have characters with different lengths, the CHARCOUNT mode is important. See https://www.ibm.com/docs/en/ssw_ibm_i_75/rzasd/charcount.htm for information about how to set the CHARCOUNT mode for a statement or an individual built-in function.

When your statement is in natural mode, the second parameter represents the number of characters, which can be different from the number of bytes or the number of double bytes for UTF-16 data.

When your statement is in standard-character-size mode, the second parameter represents the number of bytes or double-bytes.

In the following example, UTF-8 characters 'á', 'ç', and 'ë' have two bytes and characters 'b' and 'd' have one byte. Assume this code defaults to standard mode, so the second parameter represents the number of bytes or double-bytes.

1. The built-in function returns the leftmost 3 bytes, which represent the two UTF-8 characters "áb".
2. The built-in function returns the rightmost 3 bytes, which represent the two UTF-8 characters "dë".
3. The built-in function returns the leftmost 3 characters, which represent the two UTF-8 characters "ábç".
4. The built-in function returns the rightmost 3 characters, which represent the two UTF-8 characters "çdë".

          dcl-s string varchar(10)   ccsid(*utf8) inz('ábçdë');
          dcl-s string2 varchar(10) ccsid(*utf8);

          string2 = %LEFT(string : 3);              // 1. STDCHARSIZE mode, 3 bytes
          // string2 = "áb"
          string2 = %RIGHT(string : 3);             // 2. STDCHARSIZE mode, 3 bytes
          // string2 = "dë"
          string2 = %LEFT(string : 3 : *NATURAL);   // 3. NATURAL mode, 3 characters
          // string2 = "ábc"
          string2 = %RIGHT(string : 3 : *NATURAL);  // 4. NATURAL mode, 3 characters
          // string2 = "çdë"

.                                                            .

.                                                            .