What Is The Difference between Actual and Formal Parameters In PLSQL?

What is the difference between actual and formal parameters in PLSQL? Actual parameters are the values that are provided when calling the procedure or function. Formal parameters are placeholders used in the procedure or function header to define the input values that the procedure or function expects.

In PL/SQL (Procedural Language/Structured Query Language), actual parameters and formal parameters refer to the values passed to a procedure or function and the parameters declared in the procedure or function header, respectively.

Difference between Actual and Formal Parameters In PLSQL (With Table)

Basic Terms Actual Parameters In PLSQL Formal Parameters In PLSQL
Declaration Location Declared in the header of the procedure or function. Values are passed when calling the procedure or function.
Scope Limited to the scope of the procedure or function. Exist only during the execution of the procedure or function.
Data Type Specification Data types of formal parameters are specified in the header. Data types of actual parameters must match formal parameters.
Purpose Serve as placeholders for values to be passed to the routine. Contain the actual values passed during the routine call.
Usage Used within the procedure or function to perform operations. Passed as arguments to initialize the formal parameters.
Initialization   No need for explicit initialization; automatically initialized. Must be explicitly provided with values during the call.
Number Number and order are determined by the routine’s signature. Must match the number and order of formal parameters.
Lifecycle Exists throughout the execution of the procedure or function. Exists only during the invocation of the procedure or function.
Access Accessed within the routine using their names. Accessed using the names assigned during the procedure or function call.
Example Syntax CREATE PROCEDURE example_proc(p_param1 NUMBER, p_param2 VARCHAR2) AS … example_proc(10, ‘abc’);

What Is Actual In PLSQL?

It seems there might be a slight confusion in your question. In PL/SQL, “actual” is not a specific keyword or concept by itself. However, if you are referring to actual parameters or actual arguments, I can provide clarification.

In PL/SQL, when you define a procedure or function, you specify formal parameters in the header. These formal parameters act as placeholders for values that will be passed to the routine when it is called. The actual parameters are the specific values passed during the invocation of the procedure or function.

What Is Formal In PLSQL?

In PL/SQL (Procedural Language/Structured Query Language), “formal” refers to formal parameters or formal arguments. These are parameters declared in the header of a PL/SQL procedure or function. Formal parameters act as placeholders for values that are passed to the routine when it is called.

“Formal” in PL/SQL refers to the declared parameters in the header of a procedure or function that act as placeholders for values to be passed during the routine’s invocation.

Main Difference between Actual and Formal Parameters In PLSQL

  1. Definition:
    • Formal Parameters: Declared in the procedure or function header as placeholders for values to be received.
    • Actual Parameters: Values provided during the invocation of the procedure or function.
  2. Declaration Location:
    • Formal Parameters: Declared in the header of the procedure or function.
    • Actual Parameters: Passed when calling the procedure or function.
  3. Scope:
    • Formal Parameters: Limited to the scope of the procedure or function.
    • Actual Parameters: Exist only during the execution of the procedure or function call.
  4. Data Type Specification:
    • Formal Parameters: Data types are specified in the header.
    • Actual Parameters: Data types must match the formal parameters.
  5. Initialization:
    • Formal Parameters: No explicit initialization needed; automatically initialized with provided values.
    • Actual Parameters: Must be explicitly provided with values during the call.
  6. Number and Order:
    • Formal Parameters: Number and order are determined by the routine’s signature.
    • Actual Parameters: Must match the number and order of formal parameters.
  7. Purpose:
    • Formal Parameters: Serve as placeholders for values to be passed to the routine.
    • Actual Parameters: Contain the actual values passed during the routine call.
  8. Usage:
    • Formal Parameters: Used within the procedure or function to perform operations.
    • Actual Parameters: Passed as arguments to initialize the formal parameters.
  9. Lifecycle:
    • Formal Parameters: Exist throughout the execution of the procedure or function.
    • Actual Parameters: Exist only during the invocation of the procedure or function.
  10. Access:
    • Formal Parameters: Accessed within the routine using their names.
    • Actual Parameters: Accessed using the names assigned during the procedure or function call.

Similarities between Actual and Formal Parameters In PLSQL

  1. Both play crucial roles in PL/SQL procedures and functions.
  2. Data types must agree between formal and actual parameters.
  3. Names can be the same for formal and actual parameters.
  4. The number of actual parameters must match the formal parameters.
  5. Actual parameters provide values for formal parameters.
  6. Both use pass-by-value mechanism.
  7. Used for data manipulation within procedures or functions.
  8. Defined scopes for formal and actual parameters.
  9. Enables creation of reusable and modular code.

Conclusion

In conclusion, understanding the distinction between actual and formal parameters is crucial for effective programming in PL/SQL. The formal parameters, declared in the header of a procedure or function, act as placeholders, defining the expected input values. On the other hand, actual parameters, provided during the invocation of the routine, supply concrete values to the formal parameters.

The clarity in this differentiation enhances code readability and promotes the development of modular and reusable code. By adhering to the specified data types and ensuring the correct number and order of actual parameters, developers can create robust and maintainable PL/SQL programs.

The role of formal parameters within the scope of the routine allows for focused data manipulation and encapsulation of logic. Simultaneously, the existence of actual parameters is transient, limited to the duration of the routine call, reinforcing the importance of correct parameter passing during invocation.

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