How do I read and change the value of a TEdit control?

Question

I have a Form TForm1 having 5 TEdit and 2 TBitBtn.

I also need the Program so that after inputting Numeric Data in Edit1 and Edit2 on BitBtn1Click, Edit1 and Edit2 value will summed and will be displayed in Edit3.

Answer 1

You want to do something like this:

var
  val1, val2, sum: Integer;
...
val1 := StrToInt(Edit1.Text);
val2 := StrToInt(Edit2.Text);
sum := val1 + val2;
Edit3.Text := IntToStr(sum);

If you want floating point arithmetic do it like this

var
  val1, val2, sum: Double;
...
val1 := StrToFloat(Edit1.Text);
val2 := StrToFloat(Edit2.Text);
sum := val1 + val2;
Edit3.Text := FloatToStr(sum);