Thread: need advise on if statements

Hi! I would like to seek advice or insights regarding this lengthy program that I made for an assignment and was wodering if it can be shortened or if there is something wrong with it, although it works fine.

Here's the code:

Code:

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

int main(void)
{
   char name[20];

   printf("Enter Lastname Initial: ");
   scanf("%s", name);

   if(name[0]=='a' || name[0]=='c' || name[0]=='b' || name[0]=='d' || name[0]=='e' || name[0]=='f' || name[0]=='g' || name[0]=='h' || name[0]=='i' || name[0]=='j' || name[0]=='k' || name[0]=='l' || name[0]=='m')
    {
       printf("\nLine # 2");
    }

    if(name[0]=='n' || name[0]=='o' || name[0]=='p' || name[0]=='q' || name[0]=='r' || name[0]=='s' || name[0]=='t' || name[0]=='u' || name[0]=='v' || name[0]=='w' || name[0]=='x' || name[0]=='y' || name[0]=='z')
    {
        printf("\nLine # 1");
    }

    getche();
}

Thanks for the help!! ^^

Originally Posted by jannr

Hi! I would like to seek advice or insights regarding this lengthy program that I made for an assignment and was wodering if it can be shortened or if there is something wrong with it, although it works fine.

Here's the code:

Code:

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

int main(void)
{
   char name[20];

   printf("Enter Lastname Initial: ");
   scanf("%s", name);

   if(name[0]=='a' || name[0]=='c' || name[0]=='b' || name[0]=='d' || name[0]=='e' || name[0]=='f' || name[0]=='g' || name[0]=='h' || name[0]=='i' || name[0]=='j' || name[0]=='k' || name[0]=='l' || name[0]=='m')
    {
       printf("\nLine # 2");
    }

    if(name[0]=='n' || name[0]=='o' || name[0]=='p' || name[0]=='q' || name[0]=='r' || name[0]=='s' || name[0]=='t' || name[0]=='u' || name[0]=='v' || name[0]=='w' || name[0]=='x' || name[0]=='y' || name[0]=='z')
    {
        printf("\nLine # 1");
    }

    getche();
}

Thanks for the help!! ^^

instead of checking first with each alphabet try...

Code:

if(name[0]<'n')
    {
       printf("\nLine # 2");
    }
    else
    {
        printf("\nLine # 1");
    }

Originally Posted by subhash.rao

instead of checking first with each alphabet try...

Code:

if(name[0]<'n')
    {
       printf("\nLine # 2");
    }
    else
    {
        printf("\nLine # 1");
    }

ahh,, It works!! Thanks! I thought that c won't recognize alphabets in counting. lol,, so here's another question, do this run on turbo c?

ya...it should work...but if some one enters a digit for the first place it will print line # 2...

Originally Posted by subhash.rao

ya...it should work...but if some one enters a digit for the first place it will print line # 2...

Thanks! then I'll just have to instruct the user only to enter alphabets,, ^^

Thanks agen subhash.rao,, ^^

u can use isaplha function present in ctype.h to check whether the entered value is a alphabet or not......

Thanks!!

Hi again. what's wrong with this code?

Code:

#include <stdio.h>
#include <conio.h>

int main(void)
{
   char name[20];

   printf("Enter Lastname Initial: ");
   scanf("%s", name);

   if(name[0]<'N')
    {
       printf("\nLine # 2");
    }

   if(name[0]>='N')
    {
        printf("\nLine # 1");
    }


    getche();
}

when I input the small letter m it prints Line # 1 rather than Line # 2,,
Ps. I'm using if's only because we haven't discussed else yet,,

Originally Posted by Matticus

That's because, according to the ASCII chart, small 'm' is greater than big 'N'.

You can always expand your current "if()" statements to take upper/lowercase into account:

Code:

// warning; code untested, for reference only

if((name[0]>='A' && name[0]<='M') || (name[0]>='a' && name[0]<='m'))
    {
       printf("\nLine # 2");
    }

if((name[0]>='N' && name[0]<='Z') || (name[0]>='n' && name[0]<='z'))
    {
        printf("\nLine # 1");
    }

Thanks Matticus! but why is it like that?

Every character has a unique numeric code, as per the link to the ASCII table I provided. The characters that represent uppercase letters occur earlier in the table than the characters that represent lowercase letters.

If we study the table, we see that:

- 'A' has a decimal value of 65
- 'M' has a decimal value of 77
- 'N' has a decimal value of 78
- 'Z' has a decimal value of 90

- 'a' has a decimal value of 97
- 'm' has a decimal value of 109
- 'n' has a decimal value of 110
- 'z' has a decimal value of 122

So therefore,

Code:

if((name[0]>='A' && name[0]<='M') || (name[0]>='a' && name[0]<='m'))

is equivalent to,

Code:

if((name[0]>=65 && name[0]<=77) || (name[0]>=97 && name[0]<=109))

Which basically says "if the variable is in the range of uppercase 'A' to uppercase 'M', or in the range of lowercase 'a' to lowercase 'm', then print out message."

ahh,, that's right,, thanks a lot Matticus,, that clears things up,, ^^