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 - Variable Length Number of Arguments

In C programming, you can work with a variable number of arguments in a function using ellipsis (...) and the <stdarg.h> library. This feature allows you to create functions that can accept different numbers of arguments at runtime. Such functions are commonly referred to as variadic functions.

Example:


#include <stdio.h>
#include <stdarg.h>

// A variadic function that calculates the sum of its arguments
int sum(int count, ...) {
    int result = 0;

    // Declare a va_list to hold the variable arguments
    va_list args;

    // Initialize the va_list with the variable arguments
    va_start(args, count);

    // Iterate through the arguments and calculate the sum
    for (int i = 0; i < count; i++) {
        int num = va_arg(args, int); // Get the next argument
        result += num;
    }

    // Clean up the va_list
    va_end(args);

    return result;
}

int main() {
    int total1 = sum(3, 10, 20, 30); // Sum of three integers
    int total2 = sum(4, 5, 15, 25, 35); // Sum of four integers

    printf("Total 1: %d\n", total1);
    printf("Total 2: %d\n", total2);

    return 0;
}

In this example:

  • The sum function accepts a variable number of integer arguments. The first argument, count, specifies the number of arguments that follow.
  • Inside the sum function, a va_list object (args) is declared to hold the variable arguments.
  • The va_start macro initializes the va_list with the variable arguments.
  • A loop iterates through the arguments, and va_arg retrieves each argument.
  • After processing the arguments, the va_end macro cleans up the va_list.

When you call sum with a specified number of arguments, it calculates the sum of those arguments. The function is flexible and can handle a different number of arguments each time it's called.

Output:


Total 1: 60
Total 2: 80

Variadic functions are commonly used in C for functions like printf and scanf, which accept a variable number of arguments for formatting and parsing. They provide flexibility and convenience when designing functions that need to work with different numbers of inputs.

Previous
Next