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 (as of 2019-04-14 in a future release version)
 1 program plusDemo(input, output, stderr);
 2 
 3 var
 4 	x: longint;
 5 	g: set of (foo, bar);
 6 	m: string;
 7 begin
 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!'
22 end.

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)

character pairs

<> (not equal)  •  := (becomes)  •  >< (symmetric difference)  •  // (double slash)