VB.NET | C# | COBOL |
---|
Program Structure |
Imports System
Namespace Hello
Class HelloWorld
Overloads Shared Sub Main(ByVal args() As String)
Dim name As String = "VB.NET"
'See if an argument was passed from the command line
If args.Length = 1 Then
name = args(0)
End If
Console.WriteLine("Hello, " & name & "!")
End Sub
End Class
End Namespace
End Class |
using System;
namespace Hello
{
public class HelloWorld
{
public static void Main(string[] args)
{
string name = "C#";
if (args.Length == 1)
{
name = args[0];
}
Console.WriteLine("Hello, " + name + "!");
}
}
} |
$set sourceformat(free)
$set ilusing"System"
*> Note, no direct syntax for specifying a default namespace;
class-id. HelloWorld as "Hello.Helloworld".
static.
method-id. Main.
local-storage section.
01 nam string.
procedure division using by value args as string occurs any.
*> See if an argument was passed from the command line
if args::"Length" = 1
set nam to args(1)
end-if
display "Hello, ", nam, "!"
*> or, if preferred...
invoke type "Console"::"WriteLine"(string::"Concat"("Hello, ", nam, "!"))
end method Main.
end static.
end class HelloWorld. |
Comments |
' Single line only
REM Single line only
''' <summary>XML comments</summary> |
</span> |
* Single line only, "old-style" COBOL comment with '*' in column 7
*> inline comment may follow Cobol statements etc.
*>> <summary>XML comments</summary>
|
Data Types |
Value Types
Boolean
Byte, SByte
Char
Short, UShort, Integer, UInteger, Long, ULong
Single, Double
Decimal
Date
Reference Types
Object
String
Initializing
Dim correct As Boolean = True
Dim b As Byte = &H2A 'hex
Dim o As Byte = &O52 'octal
Dim person As Object = Nothing
Dim name As String = "Dwight"
Dim grade As Char = "B"c
Dim today As Date = #12/31/2007 12:15:00 PM#
Dim amount As Decimal = 35.99@
Dim gpa As Single = 2.9!
Dim pi As Double = 3.14159265
Dim lTotal As Long = 123456L
Dim sTotal As Short = 123S
Dim usTotal As UShort = 123US
Dim uiTotal As UInteger = 123UI
Dim ulTotal As ULong = 123UL
Type Information
Dim x As Integer
Console.WriteLine(x.GetType()) ' Prints System.Int32
Console.WriteLine(GetType(Integer)) ' Prints System.Int32
Console.WriteLine(TypeName(x)) ' Prints Integer
Type Conversion
Dim d As Single = 3.5
Dim i As Integer = CType(d, Integer) ' set to 4 (Banker's rounding)
i = CInt(d) ' same result as CType
i = Int(d) ' set to 3 (Int function truncates the decimal) |
Value Types
bool
byte, sbyte
char
short, ushort, int, uint, long, ulong
float, double
decimal
DateTime (not a built-in C# type)
Reference Types
object
string
Initializing
bool correct = true;
byte b = 0x2A;
object person = null;
string name = "Dwight";
char grade = 'B';
DateTime today = DateTime.Parse("12/31/2007 12:15:00");
decimal amount = 35.99m;
float gpa = 2.9f;
double pi = 3.14159265;
long lTotal = 123456L;
short sTotal = 123;
ushort usTotal = 123;
uint uiTotal = 123;
ulong ulTotal = 123;
Type Information
int x;
Console.WriteLine(x.GetType());
Console.WriteLine(typeof(int));
Console.WriteLine(x.GetType().Name);
Type Conversion
float d = 3.5f;
int i = (int)d; |
Value Types
condition-value
binary-char (unsigned)
character
binary-short, binary-long, binary-double (unsigned)
float-short, float-long
decimal
DateTime (not a built-in COBOL type
Reference types
object
string
Initializing
01 correct condition-value value true.
01 b binary-char unsigned value h"2a". *> Hex
01 o binary-char ussigned value o"52". *> Octal
01 person object value null.
01 nam string value "Dwight".
01 grade character value "B".
01 today type "DateTime" value type "DateTime"::"Parse"("12/31/2007 12:15:00").
01 amount decimal value 35.99.
01 gpa float-short value 2.9.
01 pi float-long value 3.14159265.
01 lTotal binary-double value 123456.
01 sTotal binary-short value 123.
01 usTotal binary-short unsigned value 123.
01 uiTotal binary-long value 123.
01 ulTotal binary-long unsigned value 123.
Type Information
01 x binary-long.
display x::"GetType" *> Prints System.Int32
display type of binary-long *> Prints System.Int32
display x::"GetType"::"Name" *> Prints Int32
Type Conversion
01 d float-short value 3.5. *> automatic conversion
set i to d as binary-long *> set to 3 (truncates decimal)
COBOL types not supported in C# or VB.Net
*> Only a few examples here
01 displayNumber pic 9(9).99.
01 computeNumber pic 9(9)V99.
01 alphaNumberic pic a(23).
01 binaryStorage pic x(12).
*> Also groups and redefines - a few examples
01 arecord.
03 aSubRecord pic x(10).
03 aUnion pic 9(10) redefines aSubrecord. |
Constants |
Const MAX_STUDENTS As Integer = 25
' Can set to a const or var; may be initialized in a constructor
ReadOnly MIN_DIAMETER As Single = 4.93 |
const int MAX_STUDENTS = 25;
readonly float MIN_DIAMETER = 4.93f; |
78 MAX_STUDENTS value 25. *> optionally public, binary-long...
*> Currently no direct COBOL equivalent of 'readonly' |
Enumeration |
Enum Action
Start
[Stop] ' Stop is a reserved word
Rewind
Forward
End Enum
Enum Status
Flunk = 50
Pass = 70
Excel = 90
End Enum
Dim a As Action = Action.Stop
If a <> Action.Start Then _
Console.WriteLine(a.ToString & " is " & a) ' Prints "Stop is 1"
Console.WriteLine(Status.Pass) ' Prints 70
Console.WriteLine(Status.Pass.ToString()) ' Prints Pass |
enum Action {Start, Stop, Rewind, Forward};
enum Status {Flunk = 50, Pass = 70, Excel = 90};
Action a = Action.Stop;
if (a != Action.Start)
Console.WriteLine(a + " is " + (int) a);
Console.WriteLine((int) Status.Pass);
Console.WriteLine(Status.Pass); |
*> enum Action...
enum-id. Action.
78 #Start. *> Start is a reserved word
78 #Stop.
78 #Rewind.
78 #Forward.
end enum Action.
*>enum Status...
enum-id. Stat as "Status".
78 Flunk value 50.
78 Pass value 70.
78 Excel value 90.
end enum Action.
display type "Status"::"Pass" as binary-long *> prints 70
display type "Status"::"Pass" *> prints Pass
See demo program
|
Operators |
Comparison
= < > <= >= <>
Arithmetic
+ - * /
Mod
\ (integer division)
^ (raise to a power)
Assignment
= += -= *= /= \= ^= <<= >>= &=
Bitwise
And Or Xor Not << >>
Logical
AndAlso OrElse And Or Xor Not
'Note: AndAlso and OrElse perform short-circuit logical evaluations
String Concatenation
& |
Comparison
== < > <= >= !=
Arithmetic
+ - * /
% (mod)
/ (integer division if both operands are ints)
Math.Pow(x, y)
Assignment
= += -= *= /= %= &= |= ^= <<= >>= ++ --
Bitwise
& | ^ ~ << >>
Logical
&& || & | ^ !
String Concatenation
+ |
Comparison
= < > <= >= <>
Arithmetic
+ - * /
function mod
*>no direct COBOL equivalent to integer division
**
Assignment
move, set, compute
Bitwise
b-and, b-or, b-xor, b-not, b-left, b-right
Logical
and, or, not |
Choices |
greeting = IIf(age < 20, "What's up?", "Hello")
' One line doesn't require "End If"
If age < 20 Then greeting = "What's up?"
If age < 20 Then greeting = "What's up?" Else greeting = "Hello"
' Use : to put two commands on same line
If x <> 100 And y < 5 Then x *= 5 : y *= 2
' Preferred
If x <> 100 And y < 5 Then
x *= 5
y *= 2
End If
' To break up any long single line use _
If whenYouHaveAReally < longLine And _
itNeedsToBeBrokenInto2 > Lines Then _
UseTheUnderscore(charToBreakItUp)
If x > 5 Then
x *= y
ElseIf x = 5 Then
x += y
ElseIf x < 10 Then
x -= y
Else
x /= y
End If
Select Case color ' Must be a primitive data type
Case "pink", "red"
r += 1
Case "blue"
b += 1
Case "green"
g += 1
Case Else
other += 1
End Select |
greeting = age < 20 ? "What's up?" : "Hello";
if (age < 20) greeting = "What's up?";
else
{
greeting = "Hello";
}
if (x != 100 && y < 5)
{
x *= 5;
y *= 2;
}
if (x > 5)
{
x *= y;
}
else if (x == 5)
{
x += y;
}
else if (x < 10)
{
x -= y;
}
else
{
x /= y;
}
switch (color)
{
case "pink":
case "red": r++; break;
case "blue": b++; break;
case "green": g++; break;
default: other++; break;
} |
*>greeting = age < 20 ? has no directly equivalent syntax in COBOL
if age < 20
move "What's up?" to greeting
else
move "Hello" to greeting
end-if
if x not = 100 and y < 5
multiply 5 by x
multiply 2 by y
end-if
*>No need for _ or : since statement is terminated by end-if
*> evalute is prefered in COBOL rather than if/else if/else
evaluate x
when > 5
multiply y by x
when 5
add y to x
when < 10
subtract y from x
when other
divide y into x
end-evaluate
evaluate color *> can be any type
when "pink"
when "red"
add 1 to r
when "blue"
add 1 to b
when "green"
add 1 to g
when other
add 1 to other-color
end-evaluate See demo program
|
Loops |
Pre-test Loops:
While c < 10
c += 1
End While
Do Until c = 10
c += 1
Loop
Do While c < 10
c += 1
Loop
For c = 2 To 10 Step 2
Console.WriteLine(c)
Next
Post-test Loops:
Do
c += 1
Loop While c < 10 Do
c += 1
Loop Until c = 10
Array or collection looping
Dim names As String() = {"Fred", "Sue", "Barney"}
For Each s As String In names
Console.WriteLine(s)
Next
Breaking out of loops
Dim i As Integer = 0
While (True)
If (i = 5) Then
Exit While
End If
i += 1
End While
Continue to next iteration
For i = 0 To 4
If i < 4 Then
Continue For
End If
Console.WriteLine(i) ' Only prints 4
Next |
Pre-test Loops:
while (c < 10)
{
c++;
}
for (c = 2; c <= 10; c += 2)
{
Console.WriteLine(c);
}
Post-test Loop:
do
{
c++;
} while (c < 10);
Array or collection looping
string[] names = {"Fred", "Sue", "Barney"};
foreach (string s in names)
{
Console.WriteLine(s);
}
Breaking out of loops
int i = 0;
while (true)
{
if (i == 5)
{
break;
}
i++;
}
Continue to next iteration
for (i = 0; i < 5; i++)
{
if (i < 4)
{
continue;
}
Console.WriteLine(i);
} |
Pre-test loops:
*> No WHILE keyword
perform until c >= 10
add 1 to c
end-perform
perform varying c from 2 by 2 until c > 10
display c
end-perform
Post-test loops:
perform with test after until c >= 10
add 1 to c
end-perform
Array or collection looping
01 names string occurs any.
01 s string.
set content of names to ("Fred" "Sue" "Barney")
perform varying s through names
display s
end-perform
Breaking out of loops:
01 i binary-long value 0.
perform until exit
if i = 5
exit perform
end-if
add 1 to i
end-perform
Continue to next iteration:
01 i binary-long value 0
perform varying i from 0 by 1 until i >= 5
if i < 4
exit perform cycle
end-if
display i *>Only prints 4
end-perform See demo program
|
Arrays |
Dim nums() As Integer = {1, 2, 3}
For i As Integer = 0 To nums.Length - 1
Console.WriteLine(nums(i))
Next
' 4 is the index of the last element, so it holds 5 elements
Dim names(4) As String
names(0) = "David"
names(5) = "Bobby" ' Throws System.IndexOutOfRangeException
' Resize the array, keeping the existing values (Preserve is optional)
' Note however, that this produces a new copy of the array - it is not an in-place resize!
ReDim Preserve names(6)
Dim twoD(rows-1, cols-1) As Single
twoD(2, 0) = 4.5
Dim jagged()() As Integer = { _
New Integer(4) {}, New Integer(1) {}, New Integer(2) {} }
jagged(0)(4) = 5 |
int[] nums = {1, 2, 3};
for (int i = 0; i < nums.Length; i++)
{
Console.WriteLine(nums[i]);
}
string[] names = new string[5];
names[0] = "David";
names[5] = "Bobby";
string[] names2 = new string[7];
Array.Copy(names, names2, names.Length);
float[,] twoD = new float[rows, cols];
twoD[2,0] = 4.5f;
int[][] jagged = new int[3][] {
new int[5], new int[2], new int[3] };
jagged[0][4] = 5; |
01 nums binary-long occurs any values 1, 2, 3.
*> Can also do:
set content of nums to (1 2 3)
*> 5 is the size of the array
01 names string occurs 5.
*> Can also do:
01 names string occurs any.
set size of names to 5
set names(1) to "David" *> first element indexed as 1
set names(6) to "Bobby" *> throws System.IndexOutOfRangeException
*> COBOL cannot resize an array - use copy
01 names2 string occurs 7.
invoke type "Array"::"Copy"(names, names2, names::"Length")
*> or else:
invoke names::"CopyTo"(names2, 0)
01 twoD float-short occurs any, any.
set size of twoD to rows, cols
01 jagged binary-long occurs any, occurs any.
set size of jagged to 3
set size of jagged(1) to 5
set jagged(1 5) to 5 See demo program
|
Functions |
' Pass by value (in, default), reference (in/out), and reference (out)
Sub TestFunc(ByVal x As Integer, ByRef y As Integer, ByRef z As Integer)
x += 1
y += 1
z = 5
End Sub
Dim a = 1, b = 1, c As Integer ' c set to zero by default
TestFunc(a, b, c)
Console.WriteLine("{0} {1} {2}", a, b, c) ' 1 2 5
' Accept variable number of arguments
Function Sum(ByVal ParamArray nums As Integer()) As Integer
Sum = 0
For Each i As Integer In nums
Sum += i
Next
End Function ' Or use Return statement like C#
Dim total As Integer = Sum(4, 3, 2, 1) ' returns 10
' Optional parameters must be listed last and must have a default value
Sub SayHello(ByVal name As String, Optional ByVal prefix As String = "")
Console.WriteLine("Greetings, " & prefix & " " & name)
End Sub
SayHello("Strangelove", "Dr.")
SayHello("Madonna") |
void TestFunc(int x, ref int y, out int z)
{
x++;
y++;
z = 5;
}
int a = 1, b = 1, c;
TestFunc(a, ref b, out c);
Console.WriteLine("{0} {1} {2}", a, b, c);
int Sum(params int[] nums)
{
int sum = 0;
foreach (int i in nums)
{
sum += i;
}
return sum;
}
int total = Sum(4, 3, 2, 1);
void SayHello(string name, string prefix)
{
Console.WriteLine("Greetings, " + prefix + " " + name);
}
void SayHello(string name)
{
SayHello(name, "");
} |
method-id. TestFunc.
procedure division using by value x as binary-long,
by reference y as binary-long,
output z as binary-long.
add 1 to x, y
move 5 to z
end method TestFunc.
01 a binary-long value 1.
01 b binary-long value 1.
01 c binary-long. *> c doesn't need initializing
invoke self::"TestFunc"(value a reference b output c)
*> Or
invoke self::"TestFunc"(a b c)
display a space b space c
*> sum is an intrinsic function in COBOL
01 total binary-long.
set total to function sum(4 3 2 1) *> returns 10
*> To create a non intrinsic variable argument list function:
Method-id. MySum.
01 i binary-long.
Procedure division using params nums as binary-long occurs any
returning mysum as binary-long.
Perform varying i through nums
Add i to mysum
End-perform
Goback
End method MySum.
*> then to call it:
method-id. main.
01 i binary-long.
set i to self::"MySum"(1 2 3 4)
display i
end method main.
*> COBOL doesn't support optional arguments/parameters.
*> Just create two different versions of the same function.
method-id. SayHello.
procedure division using by value nam as string, prefix as string.
display "Greetings, " prefix space nam
end method SayHello.
method-id. SayHello.
procedure division using by value nam as string.
invoke self::"SayHello"(nam "")
end method SayHello. See demo program A
See demo program B
|
Strings |
Special character constants (all also accessible from ControlChars class)
vbCrLf, vbCr, vbLf, vbNewLine
vbNullString
vbTab
vbBack
vbFormFeed
vbVerticalTab
""
' String concatenation (use & or +)
Dim school As String = "Harding" & vbTab
school = school & "University" ' school is "Harding (tab) University"
' Chars
Dim letter As Char = school.Chars(0) ' letter is H
letter = Convert.ToChar(65) ' letter is A
letter = Chr(65) ' same thing
Dim word() As Char = school.ToCharArray() ' word holds Harding
' No string literal operator
Dim msg As String = "File is c:\temp\x.dat"
' String comparison
Dim mascot As String = "Bisons"
If (mascot = "Bisons") Then ' true
If (mascot.Equals("Bisons")) Then ' true
If (mascot.ToUpper().Equals("BISONS")) Then ' true
If (mascot.CompareTo("Bisons") = 0) Then ' true
' String matching with Like - Regex is more powerful
If ("John 3:16" Like "Jo[Hh]? #:*") Then 'true
' Substring
s = mascot.Substring(2, 3)) ' s is "son"
' Replacement
s = mascot.Replace("sons", "nomial")) ' s is "Binomial"
' Split
Dim names As String = "Frank,Becky,Ethan,Braden"
Dim parts() As String = names.Split(",".ToCharArray()) ' One name in each slot
' Date to string
Dim dt As New DateTime(1973, 10, 12)
Dim s As String = "My birthday: " & dt.ToString("MMM dd, yyyy") ' Oct 12, 1973
' Integer to String
Dim x As Integer = 2
Dim y As String = x.ToString() ' y is "2"
' String to Integer
Dim x As Integer = Convert.ToInt32("-5") ' x is -5
' Mutable string
Dim buffer As New System.Text.StringBuilder("two ")
buffer.Append("three ")
buffer.Insert(0, "one ")
buffer.Replace("two", "TWO")
Console.WriteLine(buffer) ' Prints "one TWO three" |
Escape sequences
\r
\n
\t
\\
\" // quote
// String concatenation
string school = "Harding\t";
school = school + "University"; // school is "Harding (tab) University"
// Chars
char letter = school[0]; // letter is H
letter = Convert.ToChar(65); // letter is A
letter = (char)65; // same thing
char[] word = school.ToCharArray(); // word holds Harding
// String literal
string msg = @"File is c:\temp\x.dat";
// same as
string msg = "File is c:\\temp\\x.dat";
// String comparison
string mascot = "Bisons";
if (mascot == "Bisons") // true
if (mascot.Equals("Bisons")) // true
if (mascot.ToUpper().Equals("BISONS")) // true
if (mascot.CompareTo("Bisons") == 0) // true
// String matching - No Like equivalent, use Regex
// Substring
s = mascot.Substring(2, 3)) // s is "son"
// Replacement
s = mascot.Replace("sons", "nomial")) // s is "Binomial"
// Split
string names = "Frank,Becky,Ethan,Braden";
string[] parts = names.Split(",".ToCharArray()); // One name in each slot
// Date to string
DateTime dt = new DateTime(1973, 10, 12);
string s = dt.ToString("MMM dd, yyyy"); // Oct 12, 1973
// int to string
int x = 2;
string y = x.ToString(); // y is "2"
// string to int
int x = Convert.ToInt32("-5"); // x is -5
// Mutable string
System.Text.StringBuilder buffer = new System.Text.StringBuilder("two ");
buffer.Append("three ");
buffer.Insert(0, "one ");
buffer.Replace("two", "TWO");
Console.WriteLine(buffer); // Prints "one TWO three" |
Escape sequences
x"0a" *> line-feed
x"09" *> tab
"\" *> backslash
"" *> quote
*> string concatenation
01 school string value "Harding" & x"09".
set school to string::"Concat"(school, "University") *> school is "Harding (tab) University"
*> Chars
01 letter character.
01 word character occurs any.
set letter to school::"Chars"(0) *> letter is H
set letter to type "Convert"::"ToChar"(65) *> letter is A
set letter to 65 as character *> same thing
set word to school::"ToCharArray" *>word holds Harding
*> String literal
01 msg string value "File is c:\temp\x.dat".
*>String comparison
01 mascot string value "Bisons".
if mascot = "Bisons" *> true
if mascot::"Equals"("Bisons") *> true
if mascot::"ToUpper"::"Equals"("BISONS") *> true
if mascot::"CompareTo"("Bisons") = 0 *> true
*> String matching - no Like equivalent , use Regex
*> Substring
set s to mascot::"Substring"(2 3) *> s is "son"
*> Replacement
set s to mascot::"Replace"("sons" "nomial") *> s is "Binomial"
*> Split
01 names string value "Frank,Becky,Ethan,Braden".
01 parts string occurs any.
set parts to names::"Split"(",")
*> Date to string
01 dt type "DateTime" value new "DateTime"(1973, 10, 12).
01 s string.
set s to dt::"ToString"("MMM dd, yyyy") *> Oct 12, 1973
*> int to string
01 x string.
01 y binary-long value 2.
set x to type x::"ToString" *> x is "2"
*> string to int
01 x binary-long.
set x to type "Convert"::"ToInt32"("-5") *> x is -5
*> Mutable string
01 buffer type "System.Text.StringBuilder" value new "System.Text.StringBuilder"("two ").
invoke buffer::"Append"("three ")
invoke buffer::"Insert"(0, "one ")
invoke buffer::"Replace("two" "TWO"
display buffer *> Prints "one TWO three" See demo program
|
Exception Handling |
' Throw an exception
Dim ex As New Exception("Something is really wrong.")
Throw ex
' Catch an exception
Try
y = 0
x = 10 / y
Catch ex As Exception When y = 0 ' Argument and When is optional
Console.WriteLine(ex.Message)
Finally
Beep()
End Try
' Deprecated unstructured error handling
On Error GoTo MyErrorHandler
...
MyErrorHandler: Console.WriteLine(Err.Description) |
Exception up = new Exception("Something is really wrong.");
throw up;
try
{
y = 0;
x = 10 / y;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
Microsoft.VisualBasic.Interaction.Beep();
} |
*> Throw an exception
01 up type "Exception" value new "Exception"("Something is really wrong.");
raise up *> ha ha
*> Catch an exception
try
set y to 0;
compute x = 10 / y
catch (type "Exception" ex) *> Argument is optional, no "When" keyword
display ex.Message
finally
invoke type "Microsoft.VisualBasic.Interaction"::"Beep"
end-try See demo program
|
Namespaces |
Namespace Harding.Compsci.Graphics
...
End Namespace
' or
Namespace Harding
Namespace Compsci
Namespace Graphics
...
End Namespace
End Namespace
End Namespace
Imports Harding.Compsci.Graphics |
namespace Harding.Compsci.Graphics
{
...
}
namespace Harding
{
namespace Compsci
{
namespace Graphics
{
...
}
}
}
using Harding.Compsci.Graphics; |
*> At the file level
$set ilnamespace "Harding.Compsci.Graphics"
*> The directive can also be set as a project
*> level to apply the name space to all classes in the project. |
Classes / Interfaces |
' Accessibility keywords
Public
Private
Friend
Protected
Protected Friend
Shared
' Inheritance
Class FootballGame
Inherits Competition
...
End Class
' Interface definition
Interface IAlarmClock
...
End Interface
' Extending an interface
Interface IAlarmClock
Inherits IClock
...
End Interface
' Interface implementation
Class WristWatch
Implements IAlarmClock, ITimer
...
End Class |
public
private
internal
protected
protected internal
static
class FootballGame : Competition
{
...
}
interface IAlarmClock
{
...
}
interface IAlarmClock : IClock
{
...
}
class WristWatch : IAlarmClock, ITimer
{
...
} |
*> Accessibility keywords
public
private
internal
protected
protected internal
static
*> Inheritance
class-id. FootballGame inherits type "Competition".
...
end class FootballGame.
*> Interface definition
interface-id. IAlarmClock.
...
end interface IAlarmClock.
*> Extending an interface
interface-id IAlarmClock extends type "IClock".
...
end interface IAlarmClock.
*> Interface implementation
class-id. WristWatch implements type "IAlarmClock", type "ITimer".
...
end class WristWatch. See demo program
|
Constructors / Destructors |
Class SuperHero
Private _powerLevel As Integer
Public Sub New()
_powerLevel = 0
End Sub
Public Sub New(ByVal powerLevel As Integer)
Me._powerLevel = powerLevel
End Sub
Protected Overrides Sub Finalize()
' Desctructor code to free unmanaged resources
MyBase.Finalize()
End Sub
End Class |
class SuperHero
{
private int _powerLevel;
public SuperHero()
{
_powerLevel = 0;
}
public SuperHero(int powerLevel)
{
this._powerLevel= powerLevel;
}
~SuperHero()
{
}
} |
class-id. SuperHero.
01 _powerLevel binary-long.
method-id. new.
procedure division.
set _powerLevel to 0
end method new.
method-id. new.
procedure division using by value powerLevel as binary-long.
set _powerLevel to powerLevel
end method new.
method-id. Finalize override protected.
*> Destructor code to free unmanaged resources.
end method Finalize.
end class SuperHero. See demo program
|
Using Objects |
Dim hero As SuperHero = New SuperHero
' or
Dim hero As New SuperHero
With hero
.Name = "SpamMan"
.PowerLevel = 3
End With
hero.Defend("Laura Jones")
hero.Rest() ' Calling Shared method
' or
SuperHero.Rest()
Dim hero2 As SuperHero = hero ' Both reference the same object
hero2.Name = "WormWoman"
Console.WriteLine(hero.Name) ' Prints WormWoman
hero = Nothing ' Free the object
If hero Is Nothing Then _
hero = New SuperHero
Dim obj As Object = New SuperHero
If TypeOf obj Is SuperHero Then _
Console.WriteLine("Is a SuperHero object.")
' Mark object for quick disposal
Using reader As StreamReader = File.OpenText("test.txt")
Dim line As String = reader.ReadLine()
While Not line Is Nothing
Console.WriteLine(line)
line = reader.ReadLine()
End While
End Using |
SuperHero hero = new SuperHero();
hero.Name = "SpamMan";
hero.PowerLevel = 3;
hero.Defend("Laura Jones");
SuperHero.Rest();
SuperHero hero2 = hero;
hero2.Name = "WormWoman";
Console.WriteLine(hero.Name);
hero = null ;
if (hero == null)
hero = new SuperHero();
Object obj = new SuperHero();
if (obj is SuperHero)
{
Console.WriteLine("Is a SuperHero object.");
}
using (StreamReader reader = File.OpenText("test.txt"))
{
string line;
while ((line = reader.ReadLine()) != null)
{
Console.WriteLine(line);
}
} |
01 hero type "SuperHero" value new "SuperHero".
01 hero2 type "SuperHero".
01 obj object.
01 reader type "StreamReader".
01 lin string.
set hero::"Name" to "SpamMan"
set hero::"PowerLevel" to 3
invoke hero::"Defend"("Laura Jones")
invoke type "SuperHero"::"Rest" *> Calling static method
set hero2 to hero *> Both reference the same objectv
set hero2::"Name" to "WormWoman"
display hero::"Name" *> Prints WormWoman
set hero to null *> Free the object
if hero = null
set hero to new "SuperHero"
end-if
set obj to new "SuperHero"
if obj is instance of type "SuperHero"
display "Is a SuperHero object."
end-if
*> No 'using' construct in COBOL
try
set reader to type "File"::"OpenText"("test.txt")
perform until exit
set lin to reader::"ReadLine"
if lin = null
exit perform
end-if
end-perform
finally
if reader not = null
invoke reader::"Dispose"
end-if
end-try See demo program
|
Structs |
Structure StudentRecord
Public name As String
Public gpa As Single
Public Sub New(ByVal name As String, ByVal gpa As Single)
Me.name = name
Me.gpa = gpa
End Sub
End Structure
Dim stu As StudentRecord = New StudentRecord("Bob", 3.5)
Dim stu2 As StudentRecord = stu
stu2.name = "Sue"
Console.WriteLine(stu.name) ' Prints Bob
Console.WriteLine(stu2.name) ' Prints Sue |
struct StudentRecord
{
public string name;
public float gpa;
public StudentRecord(string name, float gpa)
{
this.name = name;
this.gpa = gpa;
}
}
StudentRecord stu = new StudentRecord("Bob", 3.5f);
StudentRecord stu2 = stu;
stu2.name = "Sue";
Console.WriteLine(stu.name);
Console.WriteLine(stu2.name); |
$set sourceformat(free) preservecase
valuetype-id. StudentRecord.
object.
01 #name string public.
01 gpa float-short public.
method-id. new.
procedure division using by value nam as string, gpa as float-short.
set #name to nam
set self::"gpa" to gpa
end method new.
end object.
end valuetype StudentRecord.
class-id. a.
static.
method-id. main.
01 stu type "StudentRecord" value new "StudentRecord"("Bob", 3.5).
01 stu2 type "StudentRecord".
procedure division.
set stu2 to stu
set stu2::"name" to "Sue"
display stu::"name" *> Prints Bob
display stu2::"name" *> Prints Sue
end method main.
end static.
end class a. See demo program
|
Properties |
Private _size As Integer
Public Property Size() As Integer
Get
Return _size
End Get
Set (ByVal Value As Integer)
If Value < 0 Then
_size = 0
Else
_size = Value
End If
End Set
End Property
foo.Size += 1 |
private int _size;
public int Size
{
get
{
return _size;
}
set
{
if (value < 0)
{
_size = 0;
}
else
{
_size = value;
}
}
}
foo.Size++; |
$set sourceformat(free) preservecase
class-id. MyClass.
object.
01 _size binary-long private.
method-id. get property #Size.
procedure division returning ret as binary-long.
set ret to _size
end method.
method-id. set property #Size.
procedure division using by value val as binary-long.
if val < 0
set _size to 0
else
set _size to val
end-if
end method.
end object.
end class MyClass.
class-id. a.
static.
method-id. main.
01 foo type "MyClass" value new"MyClass".
add 1 to foo::"Size"
display foo::"Size"
end method main.
end static.
end class a. See demo program
|
Delegates / Events |
Delegate Sub MsgArrivedEventHandler(ByVal message As String)
Event MsgArrivedEvent As MsgArrivedEventHandler
' or to define an event which declares a delegate implicitly
Event MsgArrivedEvent(ByVal message As String)
AddHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback
' Won't throw an exception if obj is Nothing
RaiseEvent MsgArrivedEvent("Test message")
RemoveHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback
Imports System.Windows.Forms
Dim WithEvents MyButton As Button ' WithEvents can't be used on local variable
MyButton = New Button
Private Sub MyButton_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyButton.Click
MessageBox.Show(Me, "Button was clicked", "Info", _
MessageBoxButtons.OK, MessageBoxIcon.Information)
End Sub |
delegate void MsgArrivedEventHandler(string message);
event MsgArrivedEventHandler MsgArrivedEvent;
MsgArrivedEvent += new MsgArrivedEventHandler(My_MsgArrivedEventCallback);
MsgArrivedEvent("Test message");
MsgArrivedEvent -= new MsgArrivedEventHandler(My_MsgArrivedEventCallback);
using System.Windows.Forms;
Button MyButton = new Button();
MyButton.Click += new System.EventHandler(MyButton_Click);
private void MyButton_Click(object sender, System.EventArgs e)
{
MessageBox.Show(this, "Button was clicked", "Info",
MessageBoxButtons.OK, MessageBoxIcon.Information);
} |
$set sourceformat(free) preservecase
$set ilusing"System"
delegate-id. MsgArrivedEventHandler.
procedure division using by value messag as string.
end delegate MsgArrivedEventHandler.
class-id. a.
static.
01 MsgArrivedEvent type "MsgArrivedEventHandler" event.
*> Delegates must be used with events in COBOL
method-id. main.
set MsgArrivedEvent to type "Delegate"::"Combine"
(
MsgArrivedEvent,
new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")
) as type "MsgArrivedEventHandler"
invoke MsgArrivedEvent::"Invoke"("Test message") *> Throws exception if obj is null
set MsgArrivedEvent to type "Delegate"::"Remove"
(
MsgArrivedEvent,
new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback")
) as type "MsgArrivedEventHandler"
invoke self::"add_MsgArrivedEvent"
(new "MsgArrivedEventHandler"(self::"My_MsgArrivedEventCallback"))
invoke MsgArrivedEvent::"Invoke"("Test message 2")
end method main.
method-id. My_MsgArrivedEventCallback.
procedure division using by value str as string.
display str
end method My_MsgArrivedEventCallback.
end static.
end class a. See demo program
|