String

If the two values and the operator are entered in that order separated by spaces (for example: 2 3 +), then you can separate the string and perform the calculation as follows:

private void button1_Click(object sender, EventArgs e)

{

string[] items = textBox1.Text.Trim().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

if (items.Length != 3)

{

MessageBox.Show("There must be two operands and one operator");

textBox1.Focus();

return;

}

decimal val1, val2;

// note that zero will be used if values are not valid numbers

decimal.TryParse(items[0], out val1);

decimal.TryParse(items[1], out val2);

if (items[2].Length > 1)

{

MessageBox.Show("Invalid operator");

textBox1.Focus();

return;

}

char op = items[2][0];

decimal result = 0;

switch (op)

{

case '+':

result = val1 + val2;

break;

case '-':

result = val1 - val2;

break;

case 'x':

case 'X':

case '*':

result = val1 * val2;

break;

case '/':

if (val2 != 0)

{

result = val1 / val2;

break;

}

else

{

MessageBox.Show("Can't divide by zero");

textBox1.Focus();

return;

}

case '%':

result = val1 % val2;

break;

default:

MessageBox.Show("Invalid operator");

textBox1.Focus();

return;

}

textBox1.Text = result.ToString(); // write result back to textbox

}

1 Reply

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Vulpes12y ago
If the two values and the operator are entered in that order separated by spaces (for example: 2 3 +), then you can separate the string and perform the calculation as follows:

private void button1_Click(object sender, EventArgs e)
{
string[] items = textBox1.Text.Trim().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
if (items.Length != 3)
{
MessageBox.Show("There must be two operands and one operator");
textBox1.Focus();
return;
}

decimal val1, val2;
// note that zero will be used if values are not valid numbers
decimal.TryParse(items[0], out val1);
decimal.TryParse(items[1], out val2);

if (items[2].Length > 1)
{
MessageBox.Show("Invalid operator");
textBox1.Focus();
return;
}

char op = items[2][0];
decimal result = 0;

switch (op)
{
case '+':
result = val1 + val2;
break;

case '-':
result = val1 - val2;
break;

case 'x':
case 'X':
case '*':
result = val1 * val2;
break;

case '/':
if (val2 != 0)
{
result = val1 / val2;
break;
}
else
{
MessageBox.Show("Can't divide by zero");
textBox1.Focus();
return;
}

case '%':
result = val1 % val2;
break;

default:
MessageBox.Show("Invalid operator");
textBox1.Focus();
return;
}

textBox1.Text = result.ToString(); // write result back to textbox
}