CODEWITHSUNDEEP
c++
developer
developer

Reputation: 283

Is it ok to use the following array without initializing it?

I am learning cpp on my own through a book named Programming with Cpp by John R. Hubbard, Phd. The example below is from the same source.

#include <iostream>

using namespace std;

void read(int [], int&);
void print( int [], int);
long sum (int [], int);
const int MAXSIZE=100;

int main(){
    int a[MAXSIZE]={0}, size;
    read (a,size);
    cout << "The array has " <<size <<" elements: ";
    print (a,size);
}

void read(int a[], int& n){
    cout <<"Enter integers. Terminate with 0: \n";
    n=0;
    do{
        cout << "a ["<<n<<"]: ";
        cin >> a[n];
    }
    while (a[n++] !=0 && n<MAXSIZE);
    --n; //don't count the 0
}
void print (int a[], int n){
    for (int i=0; i<n; i++)
        cout <<a[i]<<" ";
    cout<<endl;

}

Based on the above code, I need to know:

1) Why is the array[MAXSIZE] made equal to 0 in the main() function? Is it ok to use it without initializing it?

2) What is the role of n=0 in the read() function?

Upvotes: 2

Views: 85

Answers (1)

Javier Silva Ort&#237;z
Javier Silva Ort&#237;z

Reputation: 2982

1) Why is the array[MAXSIZE] made equal to 0 in the main() function? Is it ok to use it without initializing it?

Only the first element is set to 0.The others are default initialized to 0. In this case is would be ok to use it without initializing it, that is, even without the ={0}, but only if valid integers are provided.

2) What is the role of n=0 in the read() function?

The variable n is used to index through the parameter array a. Since C++ uses zero based indexing the first element of an array is at position 0, and that's why n is set to 0 initially.

Upvotes: 2

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