Cases won't execute in Switch statement...? - switch-statement

Question

I'm trying to attempt something that seems super simple, but right now I want to throw my monitor outside out into the snow. I can't see why my switch statement is not executing when called.
Here it is:
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) // Arithmetic Button Click
{
String^ riS = dc1->Text;
String^ ciS = dc2->Text;
colint = int::Parse(dc2->Text);
std::ostringstream ss;
String^ answer;
op1 = Double::Parse(foValue->Text);
op2 = Double::Parse(soValue->Text);
// Enter switch
switch(op_sym)
{
case '+':
sum = op1 + op2;
DGV->CurrentCell = DGV->Rows[RI]->Cells[CI];
ss << sum;
answer = Convert::ToString(answer);
MessageBox::Show(answer);
DGV->CurrentCell->Value = answer;
sumLabel->Text = "TEST";
break;
case '-':
sum = op1 - op2;
break;
case '*':
sum = op1 * op2;
break;
case '/':
if (op2 == 0)
{
MessageBox::Show("Sorry, you cannot divide by zero \n Please, reselect yoru second cell operand");
secondOpText->Text = "";
}
else
{
sum = op1/op2;
}
break;
default:
MessageBox::Show("I'm sorry. Please select one of these four arithmetic symbols from the drop down list: \n +, -, *, /");
break;
}
}
I'm getting the op_sym from right above:
private: System::Void comboBox1_SelectedIndexChanged(System::Object^ sender, System::EventArgs^ e)
{
Object^ selectedItem = comboBox1->SelectedItem;
String^ cb = selectedItem->ToString();
if( cb = "+")
{
op_sym = '+';
}
if(cb = "-")
op_sym = '-';
if(cb = "/")
op_sym = '/';
if(cb = "*")
op_sym = '*';
}
op_sym has already been declared as a char at the top. If someone would inform me of my most likely, beginner's mistake, I would be much appreciate. Thanks.
EDIT
...
case '+':
{
sum = op1 + op2;
DGV->CurrentCell = DGV->Rows[RI]->Cells[CI];
ss << sum;
answer = Convert::ToString(sum);
MessageBox::Show( answer);
DGV->CurrentCell->Value = answer;
sumLabel->Text = answer;
break;
}
...
private: System::Void comboBox1_SelectedIndexChanged(System::Object^ sender, System::EventArgs^ e)
{
Object^ selectedItem = comboBox1->SelectedItem;
String^ cb = selectedItem->ToString();
if( cb == "+")
{
op_sym = '+';
}
if(cb == "-")
op_sym = '-';
if(cb == "/")
op_sym = '/';
if(cb == "*")
op_sym = '*';
}

Answer 1

Notice in your second function (comparing the actual value of the op_sym):
if( cb = "+")
{
op_sym = '+';
}
if(cb = "-")
op_sym = '-';
if(cb = "/")
op_sym = '/';
if(cb = "*")
op_sym = '*';
You're performing assignments to cb and not actually comparisons. Try using the == operator for comparing two values:
if ( cb == "+" )
...
When you want to change the value of the op_sym, you use the assignment operator (=). When you want to compare values of String's, use the comparison operator (==).
Also - Check out the API for working with String is VC++: http://msdn.microsoft.com/en-us/library/ms177218.aspx

Answer 2

single = is assignment
== is equals
if( cb == "+")
{
op_sym = '+';
}
if(cb == "-")
op_sym = '-';
if(cb == "/")
op_sym = '/';
if(cb == "*")
op_sym = '*';