Plus

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+

The symbol + (pronounced “plus”) is used to:

  • explicitly indicate the positive sign of a number,
  • add two numbers resulting to a number,
  • form a union of sets,
  • (FPC) concatenate two strings (or characters; except pchar).
  • if {$modeSwitch arrayOperators+} (default in {$mode Delphi}), concatenate arrays (since FPC 3.2.0)
  • enable a feature in a {$modeSwitch}
 1program plusDemo(input, output, stderr);
 2
 3var
 4	x: longint;
 5	g: set of (foo, bar);
 6	m: string;
 7begin
 8	// unary operator: positive sign
 9	x := +7;                    // x becomes positive 7
10	x := +$100;                 // x becomes 256
11	                            // (dollar sign denotes hexadecimal base)
12	
13	// addition
14	x := 7 + 7;                 // x becomes 14
15	x := 7 + 7 + 7 + 7 + 7 + 7; // x becomes 42
16	
17	// union of sets
18	g := [foo] + [bar];         // g becomes [foo, bar]
19	
20	// concatenation of strings and/or characters (FPC/Delphi extension)
21	m := 'Hello ' + 'world!';   // m becomes 'Hello world!'
22end.

The plus sign is also a unary operator. One can write such stupid expressions as ++++++++++++++42 which will evaluate to positive 42.

In ASCII, the character code decimal 43 (or hexadecimal 2B) is defined to be + (plus sign).

see also


navigation bar: topic: Pascal symbols
single characters

+ (plus)  •  - (minus)  •  * (asterisk)  •  / (slash)
= (equal)  •  > (greater than)  •  < (less than)
. (period)  •  : (colon)  •  ; (semi colon)
^ (hat)  •  @ (at)
$ (dollar sign)  •  & (ampersand)  •  # (hash)
' (single quote)

character pairs

<> (not equal)  •  <= (less than or equal)  •  := (becomes)  •  >= (greater than or equal)

 •  >< (symmetric difference)  •  // (double slash)