String manipulation is a fundamental aspect of programming in Control Language (CL). This module will cover the basics of handling and manipulating strings, including common operations such as concatenation, extraction, and searching within strings.

1. String Variables: How to define and use string variables in CL.
2. Concatenation: Combining multiple strings into one.
3. Substring Extraction: Extracting a part of a string.
4. String Length: Determining the length of a string.
5. Searching: Finding a substring within a string.
6. Replacing: Replacing parts of a string with another string.

In CL, strings are typically defined using the DCL (Declare) command. Here’s how you can declare a string variable:

• VAR(&MYSTRING): The name of the variable.
• TYPE(*CHAR): Specifies that the variable is a character string.
• LEN(50): The length of the string.

Concatenation is the process of joining two or more strings together. In CL, you can use the CHGVAR (Change Variable) command to concatenate strings.

• *CAT: Concatenation operator.
• The result in &FULLNAME will be John Doe.

To extract a substring from a string, you can use the %SST (Substring) built-in function.

• %SST(&FULLNAME 1 4): Extracts a substring starting at position 1 with a length of 4 characters.
• The result in &FIRSTNAME will be John.

To determine the length of a string, you can use the %LEN built-in function.

• %LEN(&FULLNAME): Returns the length of the string &FULLNAME.
• The result in &LENGTH will be 8.

To find a substring within a string, you can use the %SCAN built-in function.

• %SCAN('Doe' &FULLNAME): Searches for the substring Doe within &FULLNAME.
• The result in &POSITION will be 6.

To replace parts of a string with another string, you can use a combination of %SST and CHGVAR.

• %SST(&NEWNAME 6 3): Targets the substring starting at position 6 with a length of 3 characters.
• The result in &NEWNAME will be John Smith.

1. Declare two string variables &FIRSTNAME and &LASTNAME with lengths of 20.
2. Declare a string variable &FULLNAME with a length of 40.
3. Assign values Alice to &FIRSTNAME and Johnson to &LASTNAME.
4. Concatenate &FIRSTNAME and &LASTNAME into &FULLNAME.
5. Extract the first name from &FULLNAME and store it in a new variable &EXTRACTEDNAME.

• &EXTRACTEDNAME will contain Alice.

1. Declare a string variable &TEXT with a length of 50.
2. Assign the value Hello World to &TEXT.
3. Search for the substring World in &TEXT.
4. Replace World with CL.

• &TEXT will contain Hello CL.

In this module, you learned how to manipulate strings in CL, including concatenation, extraction, determining string length, searching, and replacing substrings. These skills are essential for handling text data and performing various string operations in your CL programs. In the next module, we will delve into control structures, which will allow you to make decisions and repeat actions in your programs.