Need to convert a string number to an integer

[357mag 2]

I need to convert a number (which I think defaults to a string) to an integer in C++ Builder:

 

void __fastcall TForm1::Button1Click(TObject *Sender)
{
	int x;
	int y;
	int sum;

	x = std::stoi (Edit1->Text);
	y = Edit2->Text;

	sum = x = y;

	Label3->Caption = "The sum is" + sum;

 

Edited May 20, 2023 by 357mag

[357mag 2]

Well I think I got part of it going.

 

    y = Edit2->Text.ToInt();

 

I think that is okay, but the answer in the Label just says "is". I think I got the same problem going on. Pointer arithmetic or something. I'll have to mess with it.

[357mag 2]

I added Ansistring(sum) and it worked.

[Roger Cigol 103]

"It worked" does not mean that the code is sensible or ideal. You don't need / want to convert the int value called sum to an AnsiiString. you actually want to convert it to a C++ Builder String type (whichi is actually a UnicodeString). So you would be better to have used 

Label3->Caption = String("The sum is ") + String(sum);

[Roger Cigol 103]

Also for simple conversions from String types to integer types you may like to use the ToIntDef() String member function. Pass this a default value which is the value returned if the String variable does not contain a valid integer.  (The ToInt() function throws an exception if the String cannot be converted to an integer).

[Remy Lebeau 1396]

void __fastcall TForm1::Button1Click(TObject *Sender)
{
	int x = Sysutils::StrToInt(Edit1->Text);
	// alternatives:
	// int x = Edit1->Text.ToInt();
	// int x = std::stoi(Edit1->Text.c_str());
	// int x = CSpinEdit1->Value; (using a TCSpinEdit instead of a TEdit)

	int y = Sysutils::StrToInt(Edit2->Text);
	// same as above...
  
	int sum = x + y;

	Label3->Caption = _D("The sum is ") + String(sum);
	// alternatives:
	// Label3->Caption = Sysutils::Format(_D("The sum is %d", ARRAYOFCONST((sum)) );
	// Label3->Caption = String{}.sprintf(_D("The sum is %d", sum);
	// Label3->Caption = std::format(L"The sum is {}", sum).c_str();
	// Label3->Caption = (std::wostringstring{} << L"The sum is " << sum).str().c_str();
}

 

Edited May 22, 2023 by Remy Lebeau

[357mag 2]

In order not to piss anyone off on the forum, I will change my code to the C++ Builder string type.