Chapter 14. Procedures, Functions, and Blocks
Procedures and functions are the heart and soul of most PL/SQL programs. A procedure is a named group of instructions—a block—that performs a specific task. A function is similar in structure to a procedure, but it returns a value (called, fittingly enough, a return value) to the block that called it. Both procedures and functions are examples of named blocks; you can also create unnamed—or anonymous—blocks of instructions.
The term “block” is a very apt description, since these groups of instructions literally form the building blocks you can use—and reuse—to create sophisticated applications. This chapter tests your ability to create a procedure or function, define parameters, and analyze a function’s design.
Beginner
14-1. | What is the difference between a procedure and function? |
14-2. | What are the four sections in a procedure or function? Which of these sections are optional, and which are required? |
14-3. | What statement do you use to return a value from within a function? Can you use this same statement in a procedure? |
14-4. | Write a procedure that displays “hello world!” on your monitor. |
14-5. | Write a function that returns the string “hello world!” |
14-6. | How many RETURNs can you place in your function? |
14-7. | Which of the following function headers are valid, and which cause compile errors?
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