My C++ Program isn't executing my cout code

Question

I am learning C++, and I am trying to make a simple program which prints 5 variables, as my book said to do this, but it is not executing my code.

#include<iostream>
using namespace std;
int main()
{
    //Program Code below
    return 0;
    char letter;    letter = 'A'; //Declared, then initialized
    int number;    number = 100; //Declared, then initialized
    float decimal = 7.5;   //Declared AND initialized
    double pi = 3.14159;   //Declared AND initialized
    bool isTrue = false; //Declared AND initialized
    cout<<"Char letter: "<<letter<<endl;
    cout<<"Int number: "<<number<<endl;
    cout<<"Float decimal: "<<decimal<<endl;
    cout<<"Double pi: "<<pi<<endl;
    cout<<"Bool isTrue: "<<isTrue<<endl;
}

Those *declared, then initialized* statements are wrong. It's declared, then assigned to. — chris, Aug 27 '13 at 13:05

score 6 · Answer 1 · answered Aug 27 '13 at 13:05

6

As soon as your code executes this line

return 0;

no other lines of your code will be executed - from a practical point of view, your program will have ended. Move this line down so that it is the last line of code executed by your main() function.

answered Aug 27 '13 at 13:05

mathematician1975

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Not quite. When `return 0` executes, the program returns from the main function. There's still a bit more that happens before actual termination. – William Pursell Aug 27 '13 at 13:07
Haha to be more pedantic, your code may still run after returning from main. Destructors of global objects. – Neil Kirk Aug 27 '13 at 13:32
@NeilKirk Rather than edit my answer, I will let your comment do the talking. – mathematician1975 Aug 27 '13 at 13:42

score 2 · Answer 2 · answered Aug 27 '13 at 13:05

2

Your problem is that you are returning from main before doing anything:

int main()
{
    return 0; // HERE!!

    // no code after return gets executed

}

answered Aug 27 '13 at 13:05

juanchopanza

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score 1 · Answer 3 · answered Aug 27 '13 at 13:06

1

Your return 0; should be at the end of main, not the start

answered Aug 27 '13 at 13:06

const_ref

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score 0 · Answer 4 · answered Aug 27 '13 at 13:10

0

Please re-position the "return 0;" statement

answered Aug 27 '13 at 13:10

Martin

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score 0 · Answer 5 · answered Aug 27 '13 at 13:19

0

Since main is a function that returns an integer, the execution of the main function is primarily to return some integral value. As soon as the value is returned, the function assumes its job is complete and hence does no longer hold the control of the program.

Your code:

#include<iostream>
using namespace std;
int main()
{
    return 0; // Function thinks its job is done hence it ignores everything after it. 
    ...some other code
}

Actually what you wish to do:

#include<iostream>
using namespace std;
int main()
{
    ... useful code
    return 0;  // Okay. Returning is alright, as the useful job is done.
}

answered Aug 27 '13 at 13:19

iluvthee07

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"execution of the main function is primarily to return some integral value" that's funny! – Neil Kirk Aug 27 '13 at 13:32
@Neil : I generally use this technique to remember to put return statements at the end of my functions. Funny I know, but I was just trying to help. – iluvthee07 Aug 27 '13 at 13:36
Did you know you don't have to put a return statement in main? It's allowed! – Neil Kirk Aug 27 '13 at 13:36
Yeah I do know, just a habit of putting it there. – iluvthee07 Aug 27 '13 at 13:37
I'm such an idiot :P. Thank you so much! I was never really informed as to what the return 0; did. – user2603709 Aug 27 '13 at 22:03

My C++ Program isn't executing my cout code

5 Answers5