Example 4
-------------------------------------------------
#include <iostream>
using namespace std;
void swap(int &x, int &y){
        int temp;
        temp = x;
        x = y;
        y = temp;
}
int main(){
        int a, b;
        cout << "a=";
        cin >> a;
        cout << "b=";
        cin >> b;

        swap(a,b);
        cout << "a="<< a << endl << "b="<<b<<endl;

        return 0;
}


Example 5
-------------------------------------------------
#include <iostream>
using namespace std;
void upper(string &word){
    int i;
    for(i=0;i<word.length();i++)
        if(word[i]>='a'&&word[i]<='z') 
            word[i]=word[i]-('a'-'A');
}

int main(){

        string word;

        cout<<"Enter a word: ";
        cin>>word;

        upper(word);

        cout << "word=" << word;

        return 0;

}


Example 6
-------------------------------------------------
#include <iostream>

using namespace std;

void input(int &n, int &i){
    do{
        cout << "Input an index: ";
        cin >> i;
    }while(i<0||i>=10);
    cout << "Input new value: ";
    cin >> n;
}
void update(int n, int i, int *nums){
    nums[i]=n;
}

void printarray(int *nums){
    int i;
    for(i=0;i<10;i++)
        cout << nums[i] << " ";
    cout << endl;
}

int main(){

    int nums[10]={1,3,5,7,9,11,13,15,17,19};
    int n, i;
        
    input(n,i);
    update(n,i,nums);
    printarray(nums);
    
    return 0;
}


Example 7
---------------------------------------------------
#include <iostream>
using namespace std;

void printarray(int b[][5]){
    int i, j;
    for(i=0;i<5;i++){
        for(j=0;j<5;j++)
            cout << b[i][j] << " ";
        cout << endl;
    }
}

int main(){

        int b[5][5]={{0, 1, 2, 3, 4},
                     {1, 2, 3, 4, 5},
                     {2, 3, 4, 5, 6},
                     {3, 4, 5, 6, 7},
                     {4, 5, 6, 7, 8}};

        printarray(b);

        return 0;
}