The "for" cyclic of question

Question

hi friends,
Why output is 10 rather not 9.
Code:

#include<iostream>
using namespace std;
void main()
{
const size_t array_size=10;
int ia[array_size];
for (size_t ix=0;ix!=array_size;++ix)
ia[ix]=ix;
cout<<ia[ix]<<endl;
}

/*
my logic is:when + + X is equal to 10, you no longer perform the body of the loop statement
right result cout<<ia[ix] output is 9,why is output is 10.
*/

thanks.

Vulpes · Answer

As the variable ix is scoped to the 'for' statement and not therefore available to the cout statement, I couldn't get it to compile under VC++ unless I changed it first to this: #include using namespace std; void main() { const size_t array_size=10; int ia[array_size]; size_t ix; /* now declared at function scope */ for (ix=0;ix!=array_size;++ix) ia[ix]=ix; cout } It then produced a garbage result i.e. whatever is in the next memory slot after ia[9]. That's because ix will have been incremented to 10 just before the expression : ix!=array_size fails and the for loop exits.

Ken H · Answer

hi Hemant Srivastava , i think this compile system question. thanks.

Hemant Srivastava · Answer

When loop exits, at that time ix would be 10 ...right! Now the line cout endl ; will be interpreted as cout 10 ] which will be out of scope of the array (as array element would be from ia[0]... ia[9]) So accessing out of scope element "ia[10]" will give any random output. It may be 10 or something else..

Ken H · Answer

hi vulpes, #include using namespace std; void main() { const size_t array_size=10; int ia[array_size]; size_t ix; /* now declared at function scope */ for (ix=0;ix!=array_size;++ix) ia[ix]=ix; cout } /* i think "cout */

Hemant Srivastava · Answer

Output is coming 9.. I just checked the same program.

The "for" cyclic of question

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Answers (5)