How can I compare two or more listboxes?

Question

I have two listboxes containing a couple of elements and I would like to find out if any of these elements can be found in both boxes - it shouldn't matter if they have the same list index or not. I'm working with visual studio 2017

Answer 1

string FirstString, SecondString;
for (int x=0; x < listBox1.Items.Count;x++)
{ //loop through first listbox
//MessageBox.Show(listBox1.Items[x].ToString());
FirstString = listBox1.Items[x].ToString();

for (int y = 0; y < listBox2.Items.Count; y++)
{
//loop through second listbox
//MessageBox.Show(listBox1.Items[y].ToString());
SecondString = listBox2.Items[y].ToString();
if (FirstString == SecondString) //compare values
{ //if equal place result in listbox3
listBox3.Items.Add(FirstString);
}
}
}

for (int x = 0; x < listBox1.Items.Count; x++)
{ //loop through firstlistbox
if (listBox2.Items.Contains(listBox1.Items[x]))
{//use Contains method to find similar object, if equal place in listbox3
listBox3.Items.Add(listBox1.Items[x].ToString());
}

Hope this helps, play around with it and have fun
}

Answer 2

Thanks so much for the quick answer, it was bugging me all day long :)