Sync

Task/Variables/BASIC/variables-1.basic

@@ -0,0 +1,16 @@
+10 LET A=1.3
+20 LET B%=1.3:       REM The sigil indicates an integer, so this will be rounded down
+30 LET C$="0121":    REM The sigil indicates a string data type. the leading zero is not truncated
+40 DIM D(10):        REM Create an array of 10 digits
+50 DIM E$(5.10):     REM Create an array of 5 strings, with a maximum length of 10 characters
+60 LET D(1)=1.3:     REM Assign the first element of d
+70 LET E$(3)="ROSE": REM Assign a value to the third string
+80 PRINT D(3):       REM Unassigned array elements have a default value of zero
+90 PRINT E$(3):      REM Ten spaces because string arrays are not dynamic
+100 PRINT E$(3);"TTA CODE": REM There will be spaces between rose and etta
+110 DIM F%(10):  REM Integers use less space than floating point values
+120 PRINT G:     REM This is an error because f has not been defined
+130 PRINT D(0):  REM This is an error because elements are numbered from one
+140 LET D(11)=6: REM This is an error because d only has 10 elements
+150 PRINT F%:    REM This is an error because we have not provided an element number
+160 END

Task/Variables/BASIC/variables-2.basic

@@ -0,0 +1,15 @@
+ 10  A = 1.7: REM LET IS NOT REQUIRED
+ 20   LET B% = 1.7: REM THE PERCENT SIGN INDICATES AN INTEGER; THIS GETS TRUNCATED DOWN
+ 30   LET C$ = "0121": REM THE DOLLAR SIGN INDICATES A STRING DATA TYPE. THE LEADING ZERO IS NOT TRUNCATED
+ 40   DIM D(20): REM CREATE AN ARRAY OF 21 FLOATING POINT NUMBERS
+ 50   DIM E$(5,10): REM CREATE A TWO DIMENSIONAL ARRAY OF 66 STRINGS
+ 60   LET D(1) = 1.3: REM ASSIGN THE SECOND ELEMENT OF D
+ 70  Y$(3) = "ROSE": REM ASSIGN A VALUE TO THE FOURTH STRING
+ 80   PRINT X: REM UNASSIGNED FLOATING POINT AND INTEGER VARIABLES HAVE A DEFAULT VALUE OF ZERO
+ 90   PRINT Y$(2): REM UNASSIGNED STRING VARIABLES ARE EMPTY
+ 100  PRINT Y$(3);"TTA CODE": REM THERE WON'T BE SPACES BETWEEN ROSE AND ETTA
+ 110 F%(10) = 0: REM IF ARRAYS ARE NOT DECLARED THEY HAVE 11 ELEMENTS BY DEFAULT; IE. DIM F%(10)
+ 120  PRINT G: REM THIS PRINTS 0 AND IS NOT AN ERROR EVEN THOUGH G HAS NOT BEEN DEFINED
+ 130  PRINT D(0): REM THIS IS NOT AN ERROR BECAUSE ELEMENTS ARE NUMBERED FROM ZERO.
+ 140  PRINT F%: REM THIS PRINTS 0 BECAUSE F% IS A DIFFERENT VARIABLE THAN THE ARRAY F%(10)
+ 150  LET D(21) = 6: REM THIS IS AN ERROR BECAUSE D ONLY HAS 21 ELEMENTS INDEXED FROM 0 TO 20.

Task/Variables/C++/variables-1.cpp

@@ -0,0 +1 @@
+int a;

Task/Variables/C++/variables-2.cpp

@@ -0,0 +1 @@
+std::vector<int> intVec;

Task/Variables/COBOL/variables-1.cobol

@@ -0,0 +1,5 @@
+MOVE 5 TO x
+MOVE FUNCTION SOME-FUNC(x) TO y
+MOVE "foo" TO z
+MOVE "values 1234" TO group-item
+SET some-index TO 5

Task/Variables/COBOL/variables-2.cobol

@@ -0,0 +1,18 @@
+01  normal-date.
+    03  year     PIC 9(4).
+    03  FILLER   PIC X VALUE "-".
+    03  month    PIC 99.
+    03  FILLER   PIC X VALUE "-".
+    03  dday     PIC 99. *> Misspelling is intentional; day is a reserved word.
+
+01  reversed-date.
+    03  dday     PIC 99.
+    03  FILLER   PIC X VALUE "-".
+    03  month    PIC 99.
+    03  FILLER   PIC X VALUE "-".
+    03  year     PIC 9(4).
+...
+PROCEDURE DIVISION.
+    MOVE "2012-11-10" TO normal-date
+    MOVE CORR normal-date TO reversed-date
+    DISPLAY reversed-date *> Shows '10-11-2012'

Task/Variables/COBOL/variables-3.cobol

@@ -0,0 +1,4 @@
+01  a PIC X(20).      *> a is a string of 20 characters.
+01  b PIC 9(10).      *> b is a 10-digit integer.
+01  c PIC 9(10)V9(5). *> c is a decimal number with a 10-digit integral part and a 5-digit fractional part.
+01  d PIC 99/99/99.   *> d is an edited number, with a slash between each pair of digits in a 6-digit integer.

Task/Variables/COBOL/variables-4.cobol

@@ -0,0 +1,10 @@
+*> Group data items do not have a picture clause.
+01  group-item. *> The 'implied' PIC for group-item is PIC X(20).
+    03  sub-data          PIC X(10).
+    03  more-sub-data     PIC X(10).
+
+*> Example use of FILLER.
+01  formatted-data.
+    03  part-one          PIC X(10).
+    03  FILLER            PIC X.
+    03  part-two          PIC X(10).

Task/Variables/COBOL/variables-5.cobol

@@ -0,0 +1,11 @@
+DATA DIVISION.
+WORKING-STORAGE SECTION.
+01  initialized-data      PIC X(15) VALUE "Hello, World!".
+01  other-data            PIC X(15).
+...
+PROCEDURE DIVISION.
+    DISPLAY initialized-data *> Shows 'Hello, World!'
+    DISPLAY other-data       *> Will probably show 15 spaces.
+    ...
+    *> Sets initialized-data back to "Hello, World!" and fills other-data with spaces.
+    INITIALIZE initialized-data, other-data

Task/Variables/COBOL/variables-6.cobol

@@ -0,0 +1,3 @@
+01  group-item   VALUE "Hello!12345".
+    03  a-string PIC X(6). *> Contains "Hello!"
+    03  a-number PIC 9(5). *> Contains '12345'.

Task/Variables/COBOL/variables-7.cobol

@@ -0,0 +1,8 @@
+some-str (1:1)      *> Gets the first character from the string
+some-num (1:3)      *> Get the first three digits from the number
+another-string (5:) *> Get everything from the 5th character/digit onwards.
+
+*> To get a proper array slice, you must use reference modification on its parent data item:
+some-table-area (4:6) *> Get 6 characters from the array after from the 4th char onwards
+*> To reference modify an array element
+some-table (1) (5:1)  *> Get the 5th character from the 1st element in the table

Task/Variables/Erlang/variables.erl

@@ -0,0 +1,3 @@
+two() ->
+	A_variable = 1,
+	A_variable + 1.

Task/Variables/PHP/variables.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * @author Elad Yosifon <elad.yosifon@gmail.com>
+ * @author Elad Yosifon
  */
 
 

Task/Variables/PL-I/variables.pli

@@ -1,7 +1,7 @@
 /* The PROCEDURE block and BEGIN block are used to delimit scopes. */
 
 declare i float; /* external, global variable, excluded from the */
-                 /* local ares (BEGIN block) below.              */
+                 /* local area (BEGIN block) below.              */
 begin;
    declare (i, j) fixed binary; /* local variable */
    get list (i, j);

Task/Variables/REXX/variables-2.rexx

@@ -10,3 +10,12 @@ parse var xxx   nn oo pp qq rr
                                        /*assigns    333    ───►  PP     */
                                        /*assigns     ─5    ───►  QQ     */
                                        /*assigns   "null"  ───►  RR     */
+
+cat = 'A cat is a lion in a jungle of small bushes.'
+                                       /*assigns a literal ───►  CAT    */
+
+call value 'CAT', "When the cat's away, the mice will play."
+                                       /*assigns a literal ───►  CAT    */
+yyy='CAT'
+call value yyy, "Honest as the Cat when the meat's out of reach."
+                                       /*assigns a literal ───►  CAT    */

Task/Variables/REXX/variables-3.rexx

@@ -8,12 +8,12 @@ say xxx 'or somesuch'
 exit
 
 novalue:                               /*this can be dressed up better. */
-badLine  =sigl                         /*REXX statement num that failed.*/
-badSource=sourceline(badLine)          /*REXX source statement ···      */
+badLine  =sigl                         /*REXX line number that failed.  */
+badSource=sourceline(badLine)          /*REXX source line ···           */
 badVar   =condition('D')               /*REXX var name that's ¬ defined.*/
 say
 say '*** error! ***'
-say 'undefined variable' badvar "at REXX statement number" badLine
+say 'undefined variable' badvar "at REXX line number" badLine
 say
 say badSource
 say

Task/Variables/REXX/variables-4.rexx

@@ -0,0 +1,7 @@
+var.='something' /* sets all possible compound variables of stem var. */
+x='3 '
+var.x.x.4='something else'
+Do i=1 To 5
+  a=left(i,2)
+  Say i var.a.a.4 "(tail is '"a||'.'||a||'.'||'4'"')"
+  End

Task/Variables/Racket/variables.rkt

@@ -0,0 +1,46 @@
+#lang racket
+
+;; define a variable and initialize it
+(define foo 0)
+;; increment it
+(set! foo (add1 foo))
+
+;; Racket is lexically scoped, which makes local variables work:
+(define (bar)
+  (define foo 100)
+  (set! foo (add1 foo))
+  foo)
+(bar) ; -> 101
+
+;; and it also makes it possible to have variables with a global value
+;; that are accessible only in a specific local lexical scope:
+(define baz
+  (let () ; used to create a new scope
+    (define foo 0)
+    (define (bar)
+      (set! foo (add1 foo))
+      foo)
+    bar)) ; this is the value that gets bound to `baz'
+(list (baz) (baz) (baz)) ; -> '(1 2 3)
+
+;; define a new type, and initialize a variable with an instance
+(struct pos (x y))
+(define p (pos 1 2))
+(list (pos-x p) (pos-y p)) ; -> '(1 2)
+
+;; for a mutable reference, a struct (or some specific fields in a
+;; struct) can be declared mutable
+(struct mpos (x y) #:mutable)
+(define mp (mpos 1 2))
+(set-mpos-x! mp 11)
+(set-mpos-y! mp 22)
+(list (mpos-x mp) (mpos-y mp)) ; -> '(11 22)
+
+;; but for just a mutable value, we have boxes as a builtin type
+(define b (box 10))
+(set-box! b (add1 (unbox b)))
+(unbox b) ; -> 11
+
+;; (Racket has many more related features: static typing in typed
+;; racket, structs that are extensions of other structs,
+;; pattern-matching on structs, classes, and much more)