using if statement

[wonderpoop]

Not sure where I got lost

:
#include <stdio.h>
#include <math.h>

int main()
{
  int opselect;
  float A, S;
 
  printf("Please type in one of the following letters:");
  printf("\nA to add three numbers:");
  printf("\nS to subtract two number:");
  scanf("%d" &opselect);
  printf("Please type in three numbers:\n");
  scanf("%f", &A);
  scanf("%f", &A);
  scanf("%f", &A);
  printf("Please type in two numbers");
  scanf("%f", &S);
  scanf("%f", &S);
    
  switch (opselect);
}
 Add:
  if (A != a);
  printf("The total of two numbers is %.2f\n", (A+A+A));
  else
  printf("Please type in capital A");
  break;

 Subtract:
  if (S != s);
  printf("Three numbers subtracted is %.2f\n", (S-S));
  else
  printf("Please type in capital S);
  break;    
{
   return 0;
}

[Dave_Sinkula]

Your code doesn't seem to be very coherent, and you have a number of misplaced semicolons. Regarding the first, could you explain what you want the code to do. For the second, back up in your reference.

[wonderpoop]

Your code doesn't seem to be very coherent, and you have a number of misplaced semicolons. Regarding the first, could you explain what you want the code to do. For the second, back up in your reference.

I need to have a user first select a letter that will

A add 3 numbers
S subtract 2 numbers

[Dave_Sinkula]

User Input: Strings and Numbers [C]

[King Mir]

swich syntax is like this:

switch(expression)
{
     case val1:
          //do stuff if expression was equal to val1
     case val2:
          //do stuff if expression was equal to val2 or, after doing stuff for val1
         break;
     case val3:
          //do stuff is expression is equal to val3;
          break;
     default:
          //if expression is none of the above do this.
}

if else syntax is like this, for 1 line conditions. Note the indent. It is important to make your code easy to read.

if(epression)
     puts("The expression is true");
else
    puts("The expression is false");

So your code should be like this:

   ...

  switch (opselect)
  {
    case 'A':
      if (A != a);
        printf("The total of two numbers is %.2f\n", (A+A+A));
      else
         printf("Please type in capital A");
      break;

  case S:
    if (S != s);
      printf("Three numbers subtracted is %.2f\n", (S-S-S));
    else
      printf("Please type in capital S);
    break;    
  }
}

But that still won't work because your other code is wrong. And I have no clue what if(S != s) is supposed to do.
You should read some toutorals on reading in variables.

[JDD]

Edit: Lets go through your code first... then ill post a fixed program...

:  //Useless... 
#include <stdio.h>
#include <math.h>

int main()
{
  int opselect;
  float A, S;  // make them arrays because your taking multiple inputs... 
 
  printf("Please type in one of the following letters:");
  printf("\nA to add three numbers:");
  printf("\nS to subtract two number:");
  scanf("%d" &opselect);  // reading in a decimal when asking for a char... 
  printf("Please type in three numbers:\n");
  scanf("%f", &A);  // Putting each input into the same variable... overwriting  
  scanf("%f", &A);   // the previous each time...    
  scanf("%f", &A);
  printf("Please type in two numbers");
  scanf("%f", &S);  // same as the above... 
  scanf("%f", &S);
    
  switch (opselect);  // have no idea why your using a switch here at all...
}  // Backwards... 
 Add:
  if (A != a);  // what, why? 
  printf("The total of two numbers is %.2f\n", (A+A+A));  //This will just add the same number 3 times... 
  else
  printf("Please type in capital A");
  break;

 Subtract:
  if (S != s);  // again, what, why? 
  printf("Three numbers subtracted is %.2f\n", (S-S));  // again, subtracting the same number... 
  else
  printf("Please type in capital S);
  break;    
{
   return 0;
}

Heres a working program.

int main()
{
  char opselect;
  float A[3], S[2];
 
  printf("Please type in one of the following letters:");
  printf("\nA to add three numbers");
  printf("\nS to subtract two number");
  printf("> ");
  scanf("%c" &opselect);

  if (opselect == "A" || opselect == "a")
  {
     printf("\n\nPlease type in the first number: ");
     scanf("%f", &A[0]);
     printf("\nPlease type in the second number: ");
     scanf("%f", &A[1]);
     printf("\nPlease type in the third number: ");
     scanf("%f", &A[2]);

     printf("The total of these numbers is: %f", (A[0]+A[1]+A[2]));
   }
   elseif (opselect == "B" || opselect == "b")
   {
     printf("\n\nPlease type in the first number: ");
     scanf("%f", &B[0]);
     printf("\nPlease type in the second number: ");
     scanf("%f", &B[1]);

     printf("The difference of these numbers is: %f", (B[0]-B[1]));
   }
   else
   {
     printf("\n\nInvalid input.");
   }
     
   return 0;
}

[Salem]

> if (opselect == "A" || opselect == "a")
This "works" ???

[maxorator]

Shouldn't it be like this?

if (opselect == 'A' || opselect == 'a')

Different quotes mean different things in C++.

[wonderpoop]

this is now rewritten. My problem though is that it wants to modulate everything after I press a key. So for example, I will press A to add, it will do the add function, then it will ask me for the numbers to modulate.

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

  int main()
{
  float A[3], S[2], M[3], D[2], O[2];
  float add, subtract, multiply, divide, modulate;
  char E;
  char choice;
  
  printf("Please type in one of the following letters:");
  printf("\nA to Add three numbers: ");
  printf("\nS to Subtract two numbers: ");
  printf("\nM to Multiply three number: ");
  printf("\nD to Divide two number: ");
  printf("\nO to Modulate two number: ");
  printf("\nE to Exit program: ");
  printf("\n>");
  scanf("%c", &choice);
    
if (choice == 'A' || choice == 'a')
  {
  printf("\nPlease type in the first number: ");
  scanf("%f", &A[0]);
  printf("\nPlease type in the second number: ");
  scanf("%f", &A[1]);
  printf("\nPlease type in the third number: ");
  scanf("%f", &A[2]);
  add=A[0]+A[1]+A[2];  
  printf("\n%.2f plus %.2f plus %.2f is: %.2f", A[0], A[1], A[2], add);
  }
if (opselect == 'S' || opselect == 's')
  {
  printf("\nPlease type in the first number: ");
  scanf("%f", &S[0]);
  printf("\nPlease type in the second number: ");
  scanf("%f", &S[1]);
  subtract=S[0]-S[1];
  printf("\n%.2f minus %.2f minus %.2f is: %.2f", S[0], S[1], subtract);
  }
if (choice == 'M' || choice == 'm')
  {
  printf("\nPlease type in the first number: ");
  scanf("%f", &M[0]);
  printf("\nPlease type in the second number: ");
  scanf("%f", &M[1]);
  printf("\nPlease type in the third number: ");
  scanf("%f", &M[2]);
  multiply=M[0]*M[1]*M[2];
  printf("\n%.2f times %.2f times %.2f is: %.2f", M[0],M[1], M[2], multiply);
  }
if (choice == 'D' || choice == 'd')
  {
      printf("\nPlease type in the first number: ");
      scanf("%f", &D[0]);
      printf("\nPlease type in the second number: ");
      scanf("%f", &D[1]);
      divide=D[0]/D[1];
      printf("\n%.2f divided by %.2f is: %.2f", D[0], D[1], divide);
  }
 if (choice == 'O' || choice == 'o');
 {
   printf("\nPlease type in the first number: ");
   scanf("%f", &O[0]);
   printf("\nPlease type in the second number: ");
   scanf("%f", &O[1]);
   modulate = fmod(O[0],O[1]);
   printf("\nThe modulus of %.2f and %.2f is remainder: %.2f", O[0], O[1], modulate);
   
 }
if (choice == 'E' || choice == 'e')
   {
     printf("\nThank You and Goodbye!: ");
     scanf("%c", &E);
   }

return 0;
}

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