What is correct code to print 2 4 6 8

Question

#include <iostream>
using namespace std;

int main() {
int a;
cout<<"enter the value ofa:"<<endl;
cin>>a;
while(a<10)
cout<<"a= \n"<<a;
a=a+2;
return 0;
}

Why its output is not as i thought?

Answer 1

while (a < 10) {
if (a % 2 == 0) {
cout << a;
}

a++;
}

Answer 2

You should wrap the while-loop body in curly brackets, otherwise the loop may become infinite, because only the first line following the while-loop head will be executed, and <a> is not getting incremented.

And even by fixing that, output depends on the input.