Input function & Symbol?
<p>My friend showed me this code, he asked me what is the &amp; sign in the input parameter?</p>

<pre><code>#include&lt;iostream&gt;
using namespace std;

void f(int &amp; i, int j) {
i++;
j++;
}
int main() {
int i=1, j=2;
f(i, j);
cout &lt;&lt; ( i + j );
system ("pause");
return 0;
}
</code></pre>

<p>p.s What is the &amp; sign?</p>
