Hello World!
I'm talking about parsing numbers in C#.
And parsing means that I'm going to be able
to get the text
from a text box and
convert that to a number.
So, let's put a label...
And that's going to have my instructions
so I'm going to call it lblInstructions
and text should be something like "Enter a number:"
And let's name this txtNumber
or Num.
and no text to start with.
and then I'm going to add a button.
Let's name that btnSubmit.
And the text can say
&submit, making the "S" a hot key.
and then, I'm going to click on the form
to select it and go up here
and for the accept button,
I'm going to be pick btnSubmit.
What  that's going to do
is, when we press enter,
it will execute that submit button.
A lot of people type in a number
and then they hit enter rather than hitting the submit button.
Alright, and I need another label.
and that label is going to be called lblResult.
And I'm not going to have any text in there initially.
Now, let's double-click on that submit button,
and this is where I'm going to put my code.
So I'm going to say string "s" equals
txtNum.Text
OK, and double num
equals Double dot (.)  Parse
s, and let's say
LlblResult.Text equals
Math dot (.)  square root
of num,
and then I'm going to use my ToString function
It's a function, so we need  the parenthesis.
And let's run that.
And it says "Enter a number"
I'm going to put one two three
And hit enter.
And the square root is 11 point something.
And let's just do a test like 144,
and press enter and the square root is 12.
And that's ... And that's it!