Логический оператор || означает или
/* delete all the vowels from the string */
#include <iostream>
#include <string>
using namespace std;
int main()
{
string var1 = "";
cout << endl << "enter string :";
getline(cin, var1);
for (int i = 0; i <= var1.size(); i++)
{
if (var1[i] == 'a' || var1[i] == 'e' || var1[i] == 'i' || var1[i] == 'o' || var1[i] == 'u')
{
var1[i] = ' ';
}
}
cout << var1;
return 0;
}