Question

Write a function template named summarray, with two parameters: and array called are and an int holding the number of elements in arr. The function should return the sum of the elements in arr. this template must work for double or int arrays.

Show a sample function call to the template function you wrote.

What would you have to do to use the templates sumArray function with an array of objects of a custom class?   

Answer 1

Program

#include <iostream>
using namespace std;

template <class T>
T summarray (T arr[], int num) { // template function with two parameter
T result;
int i=0;
for(i=0;i<num;i++){
result=result+arr[i]; // summing array
}
return (result); //return result
}

int main () {
int arr[20]; // declaration
double arrdouble[20];
int ch;
int ex;
int n,i,sum;
double sumdouble;
cout<<"\n Enter number of elements for array \t";
cin>>n;
do{
    cout<<"\n 1. Sum integer elements 2. Sum double elements \t";
    cin>>ch;
    switch(ch){
        case 1: cout<<"\n Enter "<<n<<" integer number \t "; // accept integer number
        for(i=0;i<n;i++){
        cin>>arr[i];
        }
        sum=summarray<int>(arr,n); // call template function with two parameter
        cout << sum << endl;
        break;
        case 2: cout<<"\n Enter "<<n<<" double number \t "; // accept double number
        for(i=0;i<n;i++){
        cin>>arrdouble[i];
        }
        sumdouble=summarray<double>(arrdouble,n); // call template function with two parameter
        cout << sumdouble << endl;
        break;
    }
    cout<<"\n Press 0 for exit otherwise press any number \t";
    cin>>ex;
}while(ex!=0);

}

/*

output:

Enter number of elements for array     4                                                                                              

                                                                                                                                       

1. Sum integer elements 2. Sum double elements         1                                                                              

                                                                                                                                       

Enter 4 integer number          5 7 6 1                                                                                               

19                                                                                                                                     

                                                                                                                                       

Press 0 for exit otherwise press any number    5                                                                                      

                                                                                                                                       

1. Sum integer elements 2. Sum double elements         2                                                                              

                                                                                                                                       

Enter 4 double  number          5.4 1.2 0.3 8.4                                                                                       

15.3                                                                                                                                   

                                                                                                                                       

Press 0 for exit otherwise press any number    0  

*/