Calculator using if and else if statement

[shan2014]

Can anyone help me with this code. I am trying to make a calculator using if and else if statements. So far i can perform the functions of addition, subtraction , multiplication and division . But when it comes to modulus function i am getting errors.
As modulus does not support float data type i am converting to integer before i perform modulus operation.
Following are the errors:
Error 7 error C2143: syntax error : missing ';' before 'type'
Error 8 error C2143: syntax error : missing ';' before 'type'
Error 9 error C2065: 'i' : undeclared identifier
Error 10 error C2065: 'j' : undeclared identifier

I have made all the necessary declarations but i still get these errors.

This is part of the modulus function code:

else if (operation=='5')
    {
     printf("Enter the values:\n");
     scanf("%f%f", &val1,&val2);
     int i=val1;  //(error 7)
     int j=val2; //(error 8)
     remainder=i%j; //(error 9 and 10)
     printf("%f\n\n",remainder);
    }

[laserlight]

Out of curiosity, but what compiler are you using? Are you compiling with respect to the 1999 edition of the C standard or later?

[shan2014]

I am using microsoft visual studio 2012.
And I am not sure of the answer to your second question. I am fairly new at C programming.

[laserlight]

That's okay. You need to know that because you are using a Microsoft compiler, you're compiling with respect to an older edition of the C standard. In that version of C, variables must be declared at the start of a block, before other code. Thus, this:

else if (operation=='5')
{
    printf("Enter the values:\n");
    scanf("%f%f", &val1,&val2);
    int i=val1;
    int j=val2;
    remainder=i%j; //(error 9 and 10)
    printf("%f\n\n",remainder);
}

should be:

else if (operation=='5')
{
    int i;
    int j;
    printf("Enter the values:\n");
    scanf("%f%f", &val1, &val2);
    i = (int)val1;
    j = (int)val2;
    remainder = i % j;
    printf("%f\n\n", remainder);
}

Though it would be simpler to either read the values as integers to begin with, or use fmod from <math.h> if that makes sense, or cast in the modulo expression:

else if (operation=='5')
{
    printf("Enter the values:\n");
    scanf("%f%f", &val1, &val2);
    remainder = (int)val1 % (int)val2;
    printf("%f\n\n", remainder);
}

[shan2014]

Wow! thank you so much @laserlight.
I tried all except the fmod(because i don't understand) and they work flawlessly.

[Hodor]

[...]

should be:

else if (operation=='5')
{
    int i;
    int j;
    printf("Enter the values:\n");
    scanf("%f%f", &val1, &val2);
    i = (int)val1;
    j = (int)val2;
    remainder = i % j;
    printf("%f\n\n", remainder);
}

Though it would be simpler to either read the values as integers to begin with, or use fmod from <math.h> if that makes sense, or cast in the modulo expression:

else if (operation=='5')
{
    printf("Enter the values:\n");
    scanf("%f%f", &val1, &val2);
    remainder = (int)val1 % (int)val2;
    printf("%f\n\n", remainder);
}

How does that work? val1 and val2 are already (declared as) integers, so the error is actually in the scanf() conversion specifiers, not in the modulo operation.

[laserlight]

val1 and val2 are already (declared as) integers

I see that you've been peeking over shan2014's shoulder to read the declaration of val1 and val2

[Hodor]

I see that you've been peeking over shan2014's shoulder to read the declaration of val1 and val2

Err... Hodor, hodor, hodor!

[shan2014]

How does that work? val1 and val2 are already (declared as) integers, so the error is actually in the scanf() conversion specifiers, not in the modulo operation.

Just so that this air of confusion is settled, I have declared val1 and val2 as float data type (in the start of initialization) and that's why I got the error!!!

[phantomotap]

Err... Hodor, hodor, hodor!

(」゜ロ゜)」

THAT. EXPLAINS. EVERYTHING!

Soma

[Hodor]

(」゜ロ゜)」

THAT. EXPLAINS. EVERYTHING!

Of course it does.