Slash

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/

A single slash, surrounded by non-slash characters is regarded as the division operator. Two consecutive slashes are regarded as comment introducers.

division

The ASCII slash / is used in a Pascal program to perform division (∕ U+2215 “division slash”). The results are always real values. If you want to perform integer division the div operator has to be used.

A := 3 / 4;

After this operation the variable A holds the value 0.75 (assuming A is declared as a real value type, otherwise the compiler generates an incompatible type error).

related exceptions

The value on the right side of the slash must not be zero, or a division by zero error occurs. In modes where exceptions are available (e.g. ObjFPC and Delphi mode) this condition can be caught by using a try … except frame. Otherwise a run-time error occurs (RTE 200).

program divZeroDemo(input, output, stderr);

// ObjFPC mode for exceptions
{$mode objfpc}

uses
	// make exception EDivByZero known
	sysutils;

const
	dividend = 1.1;

resourcestring
	enterDivisorPrompt = 'Enter divisor:';
	divisionOperationExceptionless = 'Division did not cause an exception.';
	zeroDivisionFailure = 'Error: Attempted to divide by zero.';

var
	divisor, quotient: single;

begin
	writeLn(enterDivisorPrompt);
	readLn(divisor);
	
	try
		quotient := dividend / divisor;
		writeLn(divisionOperationExceptionless);
	except on EDivByZero do
		writeLn(zeroDivisionFailure);
	end;
end.

  Note: Exception handling is expensive.

A plain test whether the user input is non-zero would have been in the above example more sophisticated.

comment

Two slashes back to back introduce comments till the end of line. This is also known as “Delphi-style comment”.

while (buf^ in [' ', #9, #10]) do // kill separators

example source

see also

• round
• trunc