Description |
The StrToFloat function converts a number string, FloatString such as '123.456' into an Extended floating point number.
It supports integer, floating point, and scientific (exponent) formats.
If a decimal point appears in FloatString, then it must match the current DecimalSeparator value.
Version 2 of this function is for use within threads. You furnish the FormatSettings record before invoking the call. It takes a local copy of global formatting variables that make the routine thread safe.
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| Notes | The EConvertError exception is thrown if there are errors in FloatString, such as trailing blanks or invalid decimal characters.
| | Related commands | Extended | | The floating point type with the highest capacity and precision | FloatToStr | | Convert a floating point value to a string | FloatToStrF | | Convert a floating point value to a string with formatting | TFormatSettings | | A record for holding locale values for thread-safe functions |
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Example code : Converting a scientific format number string | var
stringValue : string;
floatValue : Extended;
begin
 // Set up the source string containing a number representation
stringValue := '123.456E+002';
 // Convert it to a floating point number
floatValue := StrToFloat(stringValue);
 // And display the value
ShowMessage(stringValue+' = '+FloatToStr(floatValue));
end;
| Show full unit code | 123.456E+002 = 12345.6 | Example code : Catching string conversion errors | var
A : Extended;
begin
 // We will catch conversion errors
try
A := StrToFloat('10 E 2');  // Middle blanks are not supported
except
on Exception : EConvertError do
ShowMessage(Exception.Message);
end;
try
A := StrToFloat('$FF');  // Hexadecimal values are not supported
except
on Exception : EConvertError do
ShowMessage(Exception.Message);
end;
end;
| Show full unit code | '10 E 2' is not a valid floating point value
'$FF' is not a valid floating point value |
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