如何摆脱`continue`混淆的编译器警告？

Question

编译器向我显示以下代码的以下警告:

Warning: W1036 Variable 'Address' might not have been initialized

代码(基于实际代码的MVCE代码段):

function DoFoo(): Integer;
var
  i: Integer;
  Address, Bar: Cardinal;
begin
  for i := 1 to 5 do
  begin
    try
      Address := Hex2CardPos(IntToStr(i));
    except on EConvertError do
      continue;
    end;
    Bar := Address + 42;  // "Warning: Address might not have been initialized"
  end;
  Result := 42;
end;

如您所见,Address是:

1. 分配给结果 Hex2CardPos()
2. Hex2CardPos() 抛出错误并立即跳过循环迭代.

我试图通过Address := 0;在循环开头添加一个无用的东西来解决这个问题,但是警告只是替换为另一个:

Hint: H2077 Value assigned to 'Address' never used.

这是编译器错误还是警告有实质内容？

Answer 1

问题出在您的代码中."Bar"赋值必须在try except块中,因为当异常发生时你不想分配"Bar"

function DoFoo(): Integer;
var
  i: Integer;
  Address, Bar: Cardinal;
begin
  for i := 1 to 5 do
  begin
    try
      Address := Hex2CardPos(IntToStr(i));
      Bar := Address + 42;
    except on EConvertError do
      continue;
    end;
  end;
  Result := 42;
end;

顺便说一句,这段代码"H2077 Value assigned to 'Bar' never used"是正确的.