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Abs

Synopsis


function Abs (i: integer_type): integer_type;
or
function Abs (x: real_type): real_type;
or
function Abs (z: complex_type): real_type;

Description

Returns the absolute value of the argument. For integer or real values of x, the definition is

function Abs (x: integer_or_real_type): integer_or_real_type;
begin
  if x < 0 then
    Abs := -x
  else
    Abs := x
end;

whereas for complex values it is

function Abs (x: Complex): Real;
begin
  Abs := SqRt (x * Conjugate (x))
end;

Conforming to

The function Abs is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.

Example


program AbsDemo;
var
  i1: Complex;
begin
  WriteLn (Abs (42));             { 42 }
  WriteLn (Abs (-42));            { 42 }
  WriteLn (Abs (-12.1) : 0 : 1);  { 12.1 }
  i1 := Cmplx (1, 1);             { 1 + i }
  WriteLn (Abs (i1) : 0 : 3)      { 1.414, i.e. SqRt (2) }
end.

See also

Sqr.