Format and field widths in Delphi

A ferry timetable printed as a three-column table whose numbers line up.

program StringFormat;
uses SysUtils;

const
  Route = 'Tarbert';
var
  Sailings: Integer;
  Crossing: Double;
begin
  Sailings := 6;
  Crossing := 34.5;
  // %s takes a string, %d an integer, %.2f two decimal places.
  WriteLn(Format('%s: %d sailings, %.2f minutes',
    [Route, Sailings, Crossing]));
  // A number after % is a field width; a minus sign left-aligns it.
  WriteLn(Format('%-12s%5s%9s', ['route', 'runs', 'minutes']));
  WriteLn(Format('%-12s%5d%9.2f', [Route, Sailings, Crossing]));
  WriteLn(Format('%-12s%5d%9.2f', ['Rhubodach', 18, 5.0]));
end.

How it works

1. %s takes a string, %d an integer and %.2f a number with two decimals.
2. %-12s left-aligns inside a twelve-wide field; %5d and %9.2f align right.
3. The header row and both sailing rows share those widths, so the columns match.

Keywords and builtins used here

• Double
• Format
• Integer
• WriteLn
• begin
• const
• end
• program
• uses
• var

The run, in numbers

Lines

19

Characters to type

538

Tokens

110

Three-star pace

75 tpm

At the three-star pace of 75 tokens a minute, this run takes about 88 seconds.

Type this snippet

Step 2 of 3 in Types & strings, step 5 of 27 in Language basics.

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