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Aug 17th, 2004

Sum of digits

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I want to know how to write a program to obtain sum of the first and last digit of a number?

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smithag261

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Newbie Poster

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since Jul 2004

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Aug 18th, 2004

Re: Sum of digits

Sure...

VB Code:

C++ Syntax (Toggle Plain Text)
Function sumFirstLast(number As Integer) As Integer
 
Dim numberString As String
 
numberString = Abs(number) & ""
 
sumFirstLast = Val(Mid(numberString, 1, 1)) + Val(Mid(numberString, Len(numberString), 1))
 
End Function
Function sumFirstLast(number As Integer) As Integer

Dim numberString As String

numberString = Abs(number) & ""

sumFirstLast = Val(Mid(numberString, 1, 1)) + Val(Mid(numberString, Len(numberString), 1))

End Function

Toba

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Junior Poster

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Aug 18th, 2004

Re: Sum of digits

or, in C++,

C++ Syntax (Toggle Plain Text)
int sumFirstLast( int n )
{
    char s[32];
    return ((n % 10) + (*itoa(n,s,10) - '0')); // itoa converts an int into a string
}
int sumFirstLast( int n )
{
    char s[32];
    return ((n % 10) + (*itoa(n,s,10) - '0')); // itoa converts an int into a string
}

Chainsaw

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Posting Pro in Training

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Nov 4th, 2010

-1

Re: Sum of digits

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

class sod
{
int a,b,c,i,num,num1,sum,n;
public:
void getdata()
{
cout<<"\tProgram for sum of digits\n\n\n";
cout<<"enter a one, two, three, four or five digit number ";
cin>>num;
}
void sumod()
{
sum=0;
n=0;
num1=num;
while(num1>0)
{
b=num1/10;
num1=b;
n++;
}

for(i=0;i<n;i++)
{
a=num%10;
b=num/10;
num=b;
sum=sum+a;
}

}
void putdata()
{
cout<<"\nSum of the digits of the above number is = "<<sum;
}
};

int main()
{
sod s1;
clrscr();
s1.getdata();
s1.sumod();
s1.putdata();
getch();
return 0;
}

keshalidani

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Nov 4th, 2010

-1

Re: Sum of digits

C++ Syntax:
for 4 digit:
#include<iostream.h>
#include<conio.h>

class sod
{
int a,b,c,i,n,sum;
public:
void getdata()
{
cout<<"enter a four digit number ";
cin>>n;
}
void sumod()
{
sum=0;
for(i=0;i<4;i++)
{
a=n%10;
b=n/10;
n=b;
sum=sum+a;
}
}
void putdata()
{
cout<<"\nSum of the digits of the above number is = "<<sum;
}
};

int main()
{
sod s1;
clrscr();
s1.getdata();
s1.sumod();
s1.putdata();
getch();
return 0;
}

keshalidani

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Nov 4th, 2010

Re: Sum of digits

Do you know we have a little button called [CODE] for this?

hiddepolen

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Posting Whiz in Training

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since Oct 2010

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Nov 4th, 2010

Re: Sum of digits

Or in Javascript...

C++ Syntax (Toggle Plain Text)
function sumDigits(val) {
  if (!isNaN(val)) {
    val = parseInt(val, 10) // ensure integer
    if (val>9) {
      var sum = val%10 // last digit number
      while (val>10) {  // searching for the first number
        val = parseInt(val/10, 10)
      }
      alert(sum+val)  // now what left is the last + first digit
    }
    else { alert(val) }
  }
  else { alert(val+" is not a number") }
}
function sumDigits(val) {
  if (!isNaN(val)) {
    val = parseInt(val, 10) // ensure integer
    if (val>9) {
      var sum = val%10 // last digit number
      while (val>10) {  // searching for the first number
        val = parseInt(val/10, 10)
      }
      alert(sum+val)  // now what left is the last + first digit
    }
    else { alert(val) }
  }
  else { alert(val+" is not a number") }
}

Last edited by Taywin; Nov 4th, 2010 at 12:25 pm.

Taywin

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Posting Virtuoso

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since Apr 2010

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Nov 4th, 2010

Re: Sum of digits

If n is a non-negative integer:

The last digit of n is n%10.

If n < 10, the first digit of n is n.

If n >= 10, the first digit of n is the first digit of n/10.

This is all you need to know in order to solve the problem.

arkoenig

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