arrays addition 111

[junaidkhan]

hi guys how ar you...please can anybody just sort it out,, that whats the source code to write the answer of arrays after addition.. in the below code i used 2 arrays as arguments by using functions,, and then add those arrays and it gives the answer correect,, but i want the answer in this format .. 5+5+5+5=20
6+6+6+6=24
OR the answer of your first array is =20
the answer of your second array is =24
Answer plzzzzzz???? helppppppp??????

#include <iostream>

using namespace std;
int addarray(int arg[], int length){
int r=0;
for (int i=0; i<length; i++)
r= r+arg[i];
cout<< r <<" ";
cout<<"\n";
return r;

}

int main()
{
int firstarray[]={5,5,5,5};
int secondarray[]={6,6,6,6};
addarray(firstarray,4);
addarray(secondarray,4);
return 0;
}


please i need your comments on this as soon as you people can.... I m the beginner

[JLBorges]

> but i want the answer in this format .. 5+5+5+5=20

Write another function print_array() to print out the elements of the array with a + in between.
And then call print_array() first, and then add_array()

#include <iostream>

// using namespace std; // avoid this, especially at global scope

// use whitespace to make it more readable
void print_array( const int arg[], int length, char seperator )
{
    int i = 0 ;
    for(  ; i < length-1 ; ++i )
        std::cout << arg[i] << seperator ;
    if( length > 0 ) std::cout << arg[i] ; // print the last element
}

// seperate words in identifiers with an _  (or change of case)
int add_array( const int arg[], int length ) // make it const-correct
{
    int sum = 0 ; // give this a more intuitive name
    for( int i=0; i<length; ++i ) // get into the habit of using prefix increment/decrement
        sum = sum + arg[i] ;

    // the function should just return the sum and leave the decision about what the
    //  sum is to be used for to the caller.

    return sum ;
}

int main()
{
    const int first_array[] = {5,5,5,5}; // const-correct
    const int second_array[] = {6,16,26,36,46,56}; // const-correct

    // why should we hard code magic numbers
    // when the compiler can calculate it for us?
    const int sz_first = sizeof(first_array) / sizeof( first_array[0] ) ;
    const int sz_second = sizeof(second_array) / sizeof( second_array[0] ) ;

    print_array( first_array, sz_first, '+' ) ;
    std::cout << " == " << add_array( first_array, sz_first ) << '\n' ;

    print_array( second_array, sz_second, '+' ) ;
    std::cout << " == " << add_array( second_array, sz_second ) << '\n' ;

    // there is an implicit return 0 ; here
}

http://ideone.com/tmSH56

[junaidkhan]

could you please give me some idea that why avoid using namespace std on global scope,, also give me idea about global scope please.. I am the beginner..

Also please what is STD::cout please guide me in this also

[vlad from moscow]

@junaidkhan
Also please what is STD::cout please guide me in this also

STD::cout is almost the same as std::cout but written incorrectly.:)

[junaidkhan]

i know but please give me some idea about this.. that why we use it....

[JLBorges]

> could you please give me some idea that why avoid using namespace std on global scope

Read this first: http://www.parashift.com/c++-faq/using-namespace-std.html

There is also discussion about using namespace std ; at global scope in this thread: http://v2.cplusplus.com/forum/general/72248/


> also give me idea about global scope

To simplify matters, something at global scope affects everything that follows.

using namespace std ;
// the directive in now in effect for the rest of the program
int g = 78 ; // g is visible and accessible throughout the program 

void foo()
{
    // ...
}

void bar()
{
    // ....
}

// ... 

Doing something in a local scope does not:

void foo()
{
       using namespace std ;
      // this is in effect only till the end of foo
      // ...
}
// the using directive is no longer in effect

void foo()
{
    int local = 8 ; // local is visible and accessible till end of foo 
    // ...
}
// local is not visible at this point

void bar()
{
    // ....
}

// ... 

In general, restrict programming constructs to the smallest scope possible.


> What is std::cout

It is the fully (well, almost fully) qualified name of the very same cout that you had used. It resides in a namespace called std.

Somewhat akin to:
unqualified file name: readme.txt
fully qualified filename: /home/junaid/readme.txt