C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C printf and Scanf C Data type C Token Variable in C Operators in C Comments in C Escape Sequence in C C – Storage Classes C Decision control statement Loop Statement in C Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Static Function In C Sizeof In C Selection Sort In C Scope Of Variables In C Runtime Vs Compile Time In C Random Access Lseek In C Queue Implementation In C Pseudo Code In C Prototype In C Pointer To Pointer In C Pointer Arithmetic In C Passing Array To Function In C Null Character In C Merge Sort In C Macros In C Library Functions In C Memory Leak In C Int In C Goto And Labels In C Fibonacci Series In C Fflush In C Derived Data Types In C Data Types In C Const Vs Volatile In C Character Set In C Character Class Tests In C Calloc In C C Pointers Arrays In C Include In C Clrscr In C C Vs Java String Literals In C Types Of Pointers In C Variables In C Volatile In C Why C Is A Middle Level Language Infix To Postfix Program In C Ceil function in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Armstrong program in C using function Array, Declaring Arrays and Array Initialization Limitations of Inline Function in C Merge and Merge sort with example in C Do-While Loop in C For Loop in C While-Loop in C Difference between while and do-while loop in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures In C How to Avoid Structure Padding in C Use of Structure in C Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples Entry Control Loop in C Exit control loop in C Infinite loop in C Nested loop in C pow() function in C String Handling functions in C Prime Number code in C Factorial Program in C using For Loop Factorial Program in C Using While Loop Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Prime Number Program in C using for Loop While Loop in C programming examples Built-in functions in C Assert() Function C vs Java Strings Call Back Function in Embedded C Else If Ladder fgets() function Ftell() Function getc() function getch() function gets() function Heap Sort Nested if-else statement Pi() Function Positioning of file Write() function abs() function in C Attributes in C C program to find factorial of a number using Recursion Ferror() in c fopen() function in C Fibonacci series program in C using Recursion Formatted Input and output function in C Snake Game in C User Defined Functions in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C C Program to find the Roots of a Quadratic Equation C Switch Statements Difference between rand() and srand() function in C Difference between while and for loop in C Doubly Linked list in C Example of Iteration in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C Integer Promotions in C C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Multiplication table program in C using For loop Nested Loops in C Programming Examples C Program for Mean and Median of an Unsorted Array Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Simple hash() function in C strcat() Function in C Sum of N numbers in C using For loop Use of free() function in C Write a program that produces different results in C and C++ C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Floor() Function in C Free() Function in C How to delete a file in C How to move a text in C Remove an element from an array in C Unformatted input() and output() function in C What are linker and loader in C

C Function Argument and Return Values

Functions in the C programming language are declared to avoid repeatedly writing a performable block of code; it is the same in any programming language. When it comes to the C programming language, written functions may be declared with or without any arguments. When these functions are called for execution, they may or may not return any values as the return type is not expected to be void. Still, since there are no arguments passed by us while calling it from the primary program function, we haven't sent any argument values through the call we take here.

Functions in C

In layman's terms, a Function in C programming language is a block of code that will only run or which only executes when it is called from the primary main itself or any other secondary function.

Syntax of Function in C Programming Language

void this_is_my_Function() {
  // code to be executed
}
int main(){
this_is_my_Function()   //call the function in main program
return 0;
}

Code Example

//We are Creating a function
void myFunction() {
  printf("Function has just got executed!");
}


int main() {
  myFunction(); //We are call the function from here
  return 0;
}


// Outputs "Function has just got executed!"

Output

Function has just got executed!

C Function Argument and Return Values

1.Writing functions with no arguments and no return values

Syntax and Declarations

Declaring the functions : void function();
Calling the function : function();
Defining the function :
                      void function()
                      {
                        statements;
                      }

Code

//Writing down the C programming language code for
//function with arguments and no return values
#include <stdio.h>
void value(void);
void main()
{
    value();
}
void value(void)
{
    float year_here = 2, period_is_here = 2; 
    float amount_or_money = 52000, inrate_we_have_is = 0.188;
    float sum;
    sum = amount_or_money;
    while (year_here <= period_is_here) {
        sum = sum * (1 + inrate_we_have_is);
        year_here = year_here + 1;
    }
    printf(" The total money that we are having is %f:", sum);
}

Output

The total money that we are having is 61776.000000:

2. Writing functions with argument passing but without any return values

Syntax and Declarations

Declaring the functions : void function(int);
Calling the function : function(x);
Defining the function :
             void function(int x)
             {
               statements;}

Code Example

//Writing down the C programming code for the function
//with argument but without any return value
#include <stdio.h>
void function(int, int[], char[]);
int main()
{
    int abcd = 20;
    int arrr[5] = { 110, 11120, 330, 2240, 5110 };
    char strrr[30] = "javaTpoint.com";
    function(abcd, &arrr[0], &strrr[0]);
    return 0;
}
 
void function(int abcd, int* arrr, char* strrr)
{
    int i;
    printf("value of abcd we have is %d\n\n", abcd);
    for (i = 0; i < 5; i++) {
        printf("value of arrr[%d] is %d\n", i, arrr[i]);
    }
    printf("\nvalue of strrr is %s\n", strrr);
}

Output

value of abcd we have is 20


value of arrr[0] is 110
value of arrr[1] is 11120
value of arrr[2] is 330
value of arrr[3] is 2240
value of arrr[4] is 5110


value of strrr is javaTpoint.com

3. Functions which are having no arguments passed but returns a value

Syntax and Declarations

Declaring the functions : int function();
Calling the function  : function();
Defining the function  :
                 int function()
                 {
                     statements;
                      return x;
                  }

Code Example

//Writing down the C language code for function types  with no arguments
// but which can return value upon code execution
#include <math.h>
#include <stdio.h>
int sum_fun();
int main(){
    int number;
    number = sum_fun();
    printf("\nSum of two given values we have is = %d", number);
    return 0;
}
 
int sum_fun()
{
    int abcd = 23250, bcde = 2180, sum_fun;
    sum_fun = sqrt(abcd) + sqrt(bcde);
    return sum_fun;
}

Output

Sum of two given values we have is = 199

4. Functions which have arguments passed and can also return the values to the function call

Syntax and Declarations

Declaring the functions : int function ( int );
Calling the function : function( x );
Defining the function :
             int function( int x )
             {
               statements;
               return x;
             }

Code Example

#include <stdio.h>
#include <string.h>
int function(int, int[]);
int main(){
    int i_variable, abcd = 826328362839179191739191;
    int array[5] = { 29479,2727,88765,17173,1111111 };
    abcd = function(abcd, &array[0]);
    printf("value of abcd is %d\n", abcd);
    for (i_variable = 0; i_variable < 2; i_variable++) {
        printf("value of array[%d] is %d\n", i_variable, array[i_variable]);
    }
    return 0;
}
int function(int abcd, int* array)
{
    int i_variable;
    abcd = abcd + 20;
    array[0] = array[0] + 50;
    array[1] = array[1] + 50;
    return abcd;
}

Output

value of abcd is 1790010187
value of array[0] is 29529
value of array[1] is 2777



ADVERTISEMENT
ADVERTISEMENT