CODEWITHSUNDEEP
c++io
bbjkdsfj
bbjkdsfj

Reputation: 237

why it always give zero output?

int i;
cin>>i;
cout<<i

when we entered Character i.e 'A' why it gives Zero output ?

Upvotes: 1

Views: 222

Answers (3)

phoraceus
phoraceus

Reputation: 111

because the value 'A' is not stored in the variable i since it is a integer variable. i believe that is the reason the initial value 12345 is printed on the screen...

Upvotes: 0

paxdiablo
paxdiablo

Reputation: 881983

Because A is not a numeric value suitable for storing in an integer, so it will leave your integer alone, as shown here:

#include <iostream>
int main (void) {
    int i = 12345;
    std::cin >> i;
    std::cout << i << std::endl;
    return 0;
}

When you run that code and enter A, it outputs 12345 as the value doesn't change.

If you want truly robust input, it's usually better to input lines as strings then convert them yourself.

"Mickey-mouse" programs or those where you have total control over the input can use the sort of input methods you're using, serious code should use more suitable methods.

If your intent is to convert an input character into its integer code, you can use something like:

#include <iostream>
int main (void) {
    char c;
    std::cin >> c;
    std::cout << (int)c << std::endl;
    return 0;
}

Upvotes: 7

Puppy
Puppy

Reputation: 146968

You should always check if the operation succeeded before continuing.

int i;
if (cin >> i)
    cout << i;
else
    cout << "Not a valid number!";

Upvotes: 6

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