What are Programming Languages?Types of softwaresC IntroductionC HistoryC FeaturesC ApplicationsCharacter set, ASCII TableC Programming Language Standard
Turbo C++ editor installationExploring the Turbo C++ EnvironmentC Hellow world programHow a C Program ExecuteCompilation process in C
C #include statementC Displaying OutputC Reading input from the terminalC Data typesC VariablesC Variable Naming ConventionsC ConstantsC Identifiers & Naming RulesC LiteralsC CommentsC KeywordsC Type QualifiersC TokensC Format SpecifiersC Escape SequencesC preprocessorASCII value in CStatic in CWhat are Compiler ErrorsWhat are Compiler WarningsWhat are Linker ErrorsWhat are Runtime ErrorsWhat are Logical ErrorsCompile time vs RuntimeC program to displays your name  C - Basics Practice Test.1  C - Basics Practice Test.2  C - Basics Practice Test.3  C - Basics Practice Test.4  C - Basics Practice Test.5
C Arithmetic OperatorsC Assignment OperatorsC Relational OperatorsC Logical OperatorsC Increment & Decrement OperatorsC Conditional or Ternary OperatorC Bitwise OperatorsC Type CastingC Sizeof OperatorC Comma OperatorC Operators Precedence and AssociativityC ExpressionsC Evaluation of Expressions  C - Operators Practice Test.1  C - Operators Practice Test.2  C - Operators Practice Test.3
Input-Output Library FunctionsNon-Formatted Input and OutputCharacter Oriented Library FunctionsFormatted Library FunctionsMathematical Library Functions  C - Input-Output Functions Practice Test.1
C ifC if-elseC nested if-elseC if-else-ifC switch-caseC if vs switch-caseC LoopsC while loopC do-while loopC while vs do-whileC for loopC for vs WhileC Nested LoopsC Jump Control structuresC break statementC continue statementC goto statementC continue vs goto statementC return statementC goto vs return statement  C - Control Statements Practice Test.1  C - Control Statements Practice Test.2  C - Control Statements Practice Test.3
C FunctionsC Advantages of Using FunctionsC Function PrototypeC Basic Function DesignsC Programs Using FunctionsC ScopeC Local Variable and Global VariableWhy int main() return 03 Place to declare functionsC RecursionC Base Condition in RecursionC Iteration vs RecursionC Stack Overflow Error in RecursionC Nested functionsC Variable Length Number of ArgumentsC Parameter Passing – Call by value and Call by RefC Passing Strings to FunctionsImplementation of square() functionImplementation of factorial() functionImplementation of pow(x, n) functionImplementation of reverse(int) functionImplementation of countDigits(int) functionImplementation of palindrome(int) functionImplementation of primeNumber(int) function  C - Functions Practice Test.1  C - Functions Practice Test.2
What is Array?One dimensional ArrayAccessing element of 1D arrayReading and displaying elementsPrograms on 1D ArraysTwo Dimensional ArrayAccessing Element of 2D ArrayReading and Displaying ElementsPrograms on 2D ArraysPassing 1D arrays to FunctionsPassing 2D arrays to FunctionsThree Dimensional Array  C - Array Practice Test.1  C - Array Practice Test.2
Strings in CStoring StringsC The String DelimiterC String Literals (String Constants)C Strings vs. CharactersC Declaring and Initialization of StringsC Strings and the Assignment OperatorC String Input Functions / Reading StringsC String Output Functions / Writing StringsC fscanf() and fprintf() FunctionsC Single Character Library FunctionsC String Manipulation Library FunctionsC Programs Using Character ArraysC Array of StringsC Programs Using Array of Strings  C - Strings Practice Test.1  C - Strings Practice Test.2
Pointers in CUnderstanding Memory AddressesDeclare and Initialize Pointer VariablePointer Operators in Csizeof() Operator in CPointer Advantages and DisadvantagesDereferencing/Redirecting Pointer VariablesPointer Declaration versus RedirectionConst Pointer in CVoid Pointer in CNull Pointer in CC Pointer CompatibilityArray of PointersPointer to PointerPointer ArithmeticC Functions Returning PointersC Pointer to FunctionPointers and One-Dimensional ArrayPointers and Two-Dimensional ArrayPointers and StringsDynamic Memory Allocation Functions  C - Pointers Practice Test.1  C - Pointers Practice Test.2  C - Pointers Practice Test.3
Previous
Next

C - Pointer to Function

In C, a pointer to a function is a variable that can store the address of a function. This allows you to call functions indirectly through the pointer, which can be useful for dynamic function dispatch or implementing callback mechanisms. Here's an example of how to declare, assign, and use a pointer to a function:

Example:


#include <stdio.h>

// Function to add two integers
int add(int a, int b) {
    return a + b;
}

// Function to subtract two integers
int subtract(int a, int b) {
    return a - b;
}

int main() {
    // Declare a pointer to a function that takes two integers and returns an integer
    int (*operation)(int, int);

    // Assign the address of the 'add' function to the pointer
    operation = add;

    // Use the pointer to call the 'add' function
    int result = operation(10, 5);
    printf("Addition result: %d\n", result);

    // Assign the address of the 'subtract' function to the pointer
    operation = subtract;

    // Use the pointer to call the 'subtract' function
    result = operation(10, 5);
    printf("Subtraction result: %d\n", result);

    return 0;
}

In this example:

  • We declare a pointer to a function named operation using the syntax int (*operation)(int, int);. This pointer can store the address of a function that takes two integers and returns an integer.
  • We assign the address of the add function to the operation pointer using operation = add;. Now, operation points to the add function.
  • We use the pointer to call the function indirectly by writing int result = operation(10, 5);. This invokes the add function through the pointer and stores the result in the result variable.
  • Later, we assign the address of the subtract function to the same operation pointer and use it to call the subtract function.

Output:


Addition result: 15
Subtraction result: 5

Pointer to function allows for dynamic selection of functions at runtime, making it useful in various scenarios like implementing callback mechanisms or creating extensible software where you can switch between different functions based on user input or other conditions.

Previous
Next