Editing ALGOL (section)

===Code sample comparisons===

====ALGOL 60====
(The way the bold text has to be written depends on the implementation, e.g. 'INTEGER'—quotation marks included—for integer. This is known as [[stropping (programming)|stropping]].)

 '''procedure''' Absmax(a) Size:(n, m) Result:(y) Subscripts:(i, k);
     '''value''' n, m; '''array''' a; '''integer''' n, m, i, k; '''real''' y;
 '''comment''' The absolute greatest element of the matrix a, of size n by m,
     is copied to y, and the subscripts of this element to i and k;
 '''begin'''
     '''integer''' p, q;
     y := 0; i := k := 1;
     '''for''' p := 1 '''step''' 1 '''until''' n '''do'''
         '''for''' q := 1 '''step''' 1 '''until''' m '''do'''
             '''if''' abs(a[p, q]) > y '''then'''
                 '''begin''' y := abs(a[p, q]);
                     i := p; k := q
                 '''end'''
 '''end''' Absmax

Here is an example of how to produce a [[Table (information)|table]] using Elliott 803 ALGOL.<ref>[http://www.billp.org/ccs/A104/ "803 ALGOL"] {{webarchive|url=https://web.archive.org/web/20100529063048/http://www.billp.org/ccs/A104/ |date=29 May 2010}}, the manual for Elliott 803 ALGOL</ref>

  FLOATING POINT ALGOL TEST'
  BEGIN REAL A,B,C,D'
  READ D'
  FOR A:= 0.0 STEP D UNTIL 6.3 DO
  BEGIN
    PRINT {{abbr|PUNCH(3)|sends output to the teleprinter rather than the tape punch.}},££L??'
    B := SIN(A)'
    C := COS(A)'
    PRINT PUNCH(3),{{abbr|SAMELINE|suppresses the carriage return + line feed normally printed between arguments.}},{{abbr|ALIGNED(1,6)|controls the format of the output with one digit before and six after the decimal point.}},A,B,C'
  END
  END'

====ALGOL 68====
The following code samples are ALGOL 68 versions of the above ALGOL 60 code samples.

ALGOL 68 implementations used ALGOL 60's approaches to [[stropping (programming)|stropping]]. In ALGOL 68's case tokens with the bold typeface are reserved words, types (modes) or operators.

 '''proc''' abs max = ([,]'''real''' a, '''ref''' '''real''' y, '''ref''' '''int''' i, k)'''real''':
 '''comment''' The absolute greatest element of the matrix a, of size ⌈a by 2⌈a
 is transferred to y, and the subscripts of this element to i and k; '''comment'''
 '''begin'''
    '''real''' y := 0; i := ⌊a; k := 2⌊a;
    '''for''' p '''from''' ⌊a '''to''' ⌈a '''do'''
      '''for''' q '''from''' 2⌊a '''to''' 2⌈a '''do'''
        '''if''' '''abs''' a[p, q] > y '''then'''
            y := '''abs''' a[p, q];
            i := p; k := q
        '''fi'''
      '''od'''
    '''od''';
    y
 '''end''' # abs max #

Note: lower (⌊) and upper (⌈) bounds of an array, and array slicing, are directly available to the programmer.

 floating point algol68 test:
 (
   '''real''' a,b,c,d;
   &nbsp;
   # ''printf'' – sends output to the '''file''' ''stand out''. #
   # ''printf($p$);'' – selects a ''new page'' #
   printf(($pg$,"Enter d:"));  
   read(d);
   &nbsp;
   '''for''' step '''from''' 0 '''while''' a:=step*d; a <= 2*pi '''do'''
     printf($l$);  # ''$l$'' - selects a ''new line''. #
     b := sin(a);
     c := cos(a);
     printf(($z-d.6d$,a,b,c))  # formats output with 1 digit before and 6 after the decimal point. #
   '''od'''
 )