Compare strings in C using getchar - c

Question

I know this has been asked before and I've read through the answers. I also know that my code isn't great as I'm still learning C. I'm trying, without any luck, to compare a user entered char with a char in an if statement. All and any advice is appreciated. Also, I'm aware of buffer issues though just trying to get the comparison to work first.
#include <stdio.h>
#include <math.h>
#include <string.h>
int main(void){
//int n;
//const char *F = "F";
//float temp;
//float converted;
printf("Would you like to enter Fahrenheit or Celcius? Please type F or C: ");
//scanf("%c", &a);
char input = getchar(); //This will get a single Char from the user and keep it as a char
printf("%c\n", input);
//n = strcmp(input, F);
if(input == "C") {
printf("Please enter the temp you would like to convert to Fahrenheit: ");
scanf("%f", &temp);
converted = temp * 9/5 +32;
printf("You entered %2f Celcius and that equals %2f Fahrenheit\n", temp, converted);
}else if(strcmp(input, "f") == 0) || (strcmp(input, "F") == 0){
printf("Please enter the temp you would like to convert to Celcius: ");
scanf("%f", &temp);
}else{
printf("You didn't enter F or C");
}
}

Answer 1

int strcmp ( const char * str1, const char * str2 );
strcmp takes two string variables.
but your input variable is a char. So use if(input == 'C') and if(input == 'F')

Answer 2

You are comparing characters so it should be input=='C'.
By the way don't forget to put dummy getchar() so that the \n doesn't come into the input character.
Also you are using char input in strcmp().
You have not declared temp or converted.
Note: In C you can't compare strings by using ==.
Corrected code
#include <stdio.h>
#include <math.h>
#include <string.h>
int main(void){
//int n;
//const char *F = "F";
float temp;
float converted;
printf("Would you like to enter Fahrenheit or Celcius? Please type F or C: ");
//scanf("%c", &a);
char input[10];// = getchar(); //This will get a single Char from the user and keep it as a char
scanf("%s",input);
printf("%s\n", input);
//n = strcmp(input, F);
if(strcmp(input,"C")==0) {
printf("Please enter the temp you would like to convert to Fahrenheit: ");
scanf("%f", &temp);
converted = temp * 9/5 +32;
printf("You entered %2f Celcius and that equals %2f Fahrenheit\n", temp, converted);
}else if((strcmp(input, "f") == 0) || (strcmp(input, "F") == 0)){
printf("Please enter the temp you would like to convert to Celcius: ");
scanf("%f", &temp);
}else{
printf("You didn't enter F or C");
}
}