Delphi Basics : Sqrt command

DelphiBasics

Sqrt
Function

Gives the square root of a number

System unit

function Sqrt(Number Extended):Extended;

Description

The Sqrt function returns the square root of a Number.

The number must be a floating point type.

Special values are treated as follows:

Infinity	: Infinity
-0	: -0
NaN (Not a Number)	: NaN

Notes

Warning : the square root of a negative number is an imaginary number. In Delphi, use the Math routines to handle these.

Sqrt should raise an EInvalidOp exception when the Number is negative. In practice, the author's PC crashed (running Windows ME) when attempted.

Related commands

Sqr		Gives the square of a number
Sum		Return the sum of an array of floating point values

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Example code : Find the square root of various values

var
  number, squareRoot : Extended;

begin
  // The square root of 225 = 15
  number  := 225;
  squareRoot := Sqrt(number);
  ShowMessageFmt('Square root of %f = %f',[number, squareRoot]);

  // The square root of 3.456 = 1.859...
  number  := 3.456;
  squareRoot := Sqrt(number);
  ShowMessageFmt('Square root of %7.3f = %12.12f',[number, squareRoot]);

  // The square root of infinity is still infinity
  number := Infinity;
  number := Sqrt(number);
  ShowMessageFmt('Square root of Infinity = %f',[number]);
end;

Show full unit code

  Square root of 225.0 = 15.0
  Square root of 3.456 = 1.859032006180
  Square root of Infinity = INF