下列条件语句种，功能与其他语句不同的是( )
if(a) cout << x << endl; else cout << y << endl;
if(a == 0) cout << y << endl; else cout << x << endl
if(a != 0) cout << x << endl; else cout << y << endl;
if(a == 0) cout << x << endl; else cout << y << endl;
