Write a program in C to remove the last comma from a string. The below C program takes string having comma’s in it as input and removes the last comma from the string. The program will display the processed string on the output screen.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    //Declare all the necessary variables
    char *strInput="C Programming, Tutorial site";
    char *strOutput;
    int length = 0;
    int counter = 0;
    int flag = 0;

    //Get the length of input string
    length=strlen(strInput);

    //find the position of last comma
    for(counter = length-1; counter >=0; counter--){
        if(strInput[counter]==','){
            //position of comma is at index counter
            break;
        }
    }

    if(counter >= 0){

        for(int i=0; i<length-1; i++){
            if(i == counter){
                //Skip the current index and copy the character at next index of input string
                strOutput[i] = strInput[i + 1];
                //Set flag to 1 in order to indicate we removed last comma
                flag = 1;
            }
            else{
                    if(flag==1){
                            strOutput[i] = strInput[i+1];

                    }
                    else{
                        strOutput[i] = strInput[i];
                    }

            }
        }
            printf("\nInput String: %s", &strInput[0]);
            printf("\nOutput String: %s", &strOutput[0]);
    }
    else{
            strOutput = strInput;
            printf("\nInput String: %s", &strInput[0]);
            printf("\nOutput String: %s", &strOutput[0]);
    }

    printf("\n\n");
    return 0;
}

Here is the output of the above program: