Visual Studio
Comparison of keywords in different languages
This topic lists the general programming tasks that can be outlined with a language keyword. For more information on tasks that require code samples, see Using Code Examples Compare the programming concepts in different languages.
Destination Visual BasicVisual J # C C # new JScriptvisual FoxPro declared variable
Private, Public, Friend, Protected, Static1, Shared, DIM
Public, Private, Protected Static, Final, Volatile, Transient
Declare
(Concept, not a keyword) declare (keywords include user-defined types and built-in types)
VAR
[Implicit statement]; or public, local, private declares that the named constant
Const
Final
Const
Const
Readonly
Const
New #define creates a new object
New
New
New
New
New
N / a
CreateObject
() n / a
CoCreateInstance ()
(For COM object) New activityXObject () createObject; newobject assigns an object to the object variable
=
===
=
=; Or the Store function / method does not return value
Sub
2void
Void
Void
Voidvoid (for COM Server) overload function or method (Visual Basic: overloaded process or method)
OVERLOADS
NEW (no language keyword when this purpose) (no language keyword is required) (no language keyword is required) (no language keyword when this purpose is reached) (no language keyword is required) ( Do not need any language key when this purpose is reached, reference the current object
ME
3THIS
THIS
THIS
THIS
This; thisform is non-virtual call to the virtual method of the current object
Myclass
N / AMYCLASS: FUNC1 (), where MyClass is a C class that contains FUNC1 member functions. N / A / A / A Retrieves characters from strings
GetChar function
NEW "* (p 10) or P [10], where P is char * [] STR [10], the STR here is a string,
Charat
,
Substring
,
Substr
4SUBSTR () Statement Composite Data Type (Visual Basic: Structure)
Structure
End structure
Class, Interface
Class
,
Struct
,
union
__interface
Struct
,
Class
,
Interface
Class
,
Interface
NEW N / A initialization object (constructor)
Sub new ()
5 constructor (concept, not keyword)
Constructor
(Concept, not a keyword) Constructor or system default type constructor
Constructor
(Concept, Not Keyword) 6Init Event Direct Termination Object N / A ~ ClassNamen / AN / A Tight Method Call in the system before the garbage collection recycling object 7
Finalize
New (Class_Terminate in Visual Basic 6.0) Finally Destructor N / ATESTROY Event Initialize DIM at declaration variables
X as long = 5 DIM C AS New Car (FuElTyPeenum.gas) INT X = 5; // Or initialize with constructor C C (10); int x = 5; // initialize the value: int x = 123; // or use the default constructor: int x = new int ();
VAR
X = 5
VAR
Y: car = new car () N / A Gets the address of the function
Addressof
(For class members, this operator returns a reference to the function in the form of the entrusted instance) DELEGATE, MULTICAST, / ** @Delgate * /
__delegate
Delegate
Use the function name N / A callback N / A without parentheses to pass the address of a function to another callback modulator. For example, see
Use a callback function
. Callback; Callback (IDL property) N / an / an / a declaration object can be modified asynchronously N / AVOLATILE
Volatile
Volatile
N / A / a forced explicit declaration variables
Option expedition
Not available. All variables must be declared before use. Not available. All variables must be declared before use. Not available. (All variables must first declare to use) Quick mode (open by default) _VFP.LanguageOptions New test Do not reference object variables
Obj = Nothing
POBJ == nullpobj == nullobj == nullobj == undefined obj == NulleMpty (); isnull () does not reference the value of object variables
Nothing
nulln / a
NULL
Null undefinedn / A test database empty expression
ISDBNULL
Affected
System.Data.sqltypes
Support N / A / AX == Nullisnull () Test Variant variable is initialized N / A / A / A / AX == undefinedempty () Define the default properties
DEFAULT
New "" N / A
By using an indexer
N / A / a
Object-oriented programming
Destination Visual Basicvisual J # C C # New JScriptvisual FoxPro reference base class
Mybase
New Super
__super
Base
Super
New baseclass attribute; ParentClass property; DodeFault () declaration interface
Interface
New Interface
__interface
Interface
Interface
New define class Specifies the interface to be implemented
IMPLEMENTS
(Statement) IMPLEMENTS (clause in class declaration) (only from the interface) Class C1: Public I1Class C1: I1
IMPLEMENTS
New imports new declaration
Class
NEW
Class
Class
Class
New define class myclass as
New Abstract
__ABSTRACT
8 (only in C hosted expansion)
Abstract
Abstract
NEW N / A specifies a class that cannot be inherited.
Notinheritable
New final
__sealed
(Only in C managed expansion)
SeaD
Final
NEW N / A declares an enumeration type
ENUM
END ENUM
N / a
ENUM
ENUM
ENUM
NEW N / A declares a class constant
Const
Static final (applied to field declaration)
Const
Const
(Application to field declaration)
Const
New #define derives a class from the base class
Inherits C2
New class c1 extends C2Class C1: Public Base (no language keyword to achieve this) Class C1: C2
Class C1 Extends C2
New define class myclass as parentclass rewriting method
OVERRIDES
NEW (no language keyword when this purpose) (no language key is required)
Override
(Do not need any language key when this purpose is required) (no language keyword is required) declares that a method that must be implemented in derived classes
Mustoverride
New Abstract places = 0 in the end of the declaration (pure virtual method)
Abstract
Abstract
New (no language key when this purpose is required) declares a way to rewrite
NOTOVERRIDABLE
NEW (By default, the method cannot be rewritten.) Final
__sealed
(Only in C managed expansion)
SeaD
Final
NEW N / A declares a virtual method, a Visual Basic or attribute accessor (C #, C )
OVERRIDABLE
(By default, the method is virtual)
Virtual
Virtual
(By default, the method is virtual) N / A hidden base class members in the derived class
Shadowing
N / A / A / A
New Modifier
N / A declares a reference for a type of method for class methods
Delegate
New delegate, multicast, / ** @Delgate * /
__delegate
(Only in C managed expansion)
Delegate
Use a function name without parentheses N / A specified variables to include an object to handle its event
Withevents
N / an / a (written code - no specific keyword) (Writing code - no specific keyword) EventHandler () New Specifies events to call the event procedure for it
Handles
New (event procedure can still be associated with a WitHevents variable with a named mode.) N / an / an / AN / A Distribution value of the object expression in one time to access multiple members
With objexpr <.member> <.member> end with
N / A / A / A
WITH9WITH ... ENDWITH
Abnormal processing
Destination Visual BasicVisual J # C C # New JScriptvisual FoxPro Structured Exception Processing
Try
New
Catch
Finally
END TRY
Try, catch, finaryly, throw
__TRY, __EXCEPT
,
__finally
Try, catch, finally
,
Throw
Try, catch, finally
,
Throw
OneRror (), ComreturNError (), Error (); Message (), Aerror () C exception handling N / AN / A
Try, catch, throw
N / A / A / A
Decision structure
Destination Visual Basicvisual J # C C # New JScriptvisual FoxPro Decision Structure (Selection)
Select Case ..., Case, Case Else, End Select
Switch, Case, Break, Default
Switch, Case, Default
,
goto
,
Break
Switch
, Case, DEFAULT, GOTO, BREAK
Switch, Case
,
Break
Case decision structure (if ... then)
If ... Then, Elseif ... Then, Else, End IF
IF, ELSE
IF, ELSE
IF, ELSE
IF, ELSE
IF ... ENDIF loop structure (conditional)
While, Do [While, Until] ..., loop [while, unsil]
Do, While, Continue
Do, while
,
Continue
DO
,
While
,
Continue
Do, while
,
Break, Continue
Do, while (clause) loop structure (iteration)
For ..., [exit for,] next
For Each ..., [exit for,] next
For, Break
for
for
,
Foreach
FOR (x = 0; x <10; x ) {...}
For (prop in obj) {print (obj [prop]);}
For (clause), for ... Endfor, Continue, Next
Array
Destination Visual BasicVisual J # C C # New JScriptvisual FoxPro declares an array
DIM A () As long
int [] x = new int [5];
INT X [5];
int [] x = new int [5];
Var x: int []
,
Var arr = array ()
Dimension, Declare initializes an array
DIM A () as long = {3, 4, 5}
Int [] x = {1, 2, 3, 4, 5};
INT x [5] = {1, 2, 3, 4, 5};
Int [] x = new int [5] {1, 2, 3, 4, 5};
Var x: int [] = [1, 2, 3, 4, 5]
,
Var arr = new array (1, 2, 3, 4, 5)
Dimension, Declare reassigned an array
Redim
N / A / A / A
Arr.Length = Newsize
(Only for JScript arrays) 10DIMension, Declare class
Purpose Visual BasicVisual J # C C # New JScriptvisual FoxPro visible outside the project or program
Public
public
public
public
public
NEW PUBLIC is not visible in the assembly (C # / Visual Basic) or package (Visual J #, JScript)
Friend
(Omitted the scope of keywords will specify "package range")
Private
Internal
Internal
New N / A is only visible in the project (for nested classes, visible in the included ")
Private
Private
Private
Private
Private
New Hidden
Member range
Destination Visual BasicVisual J # C C # New JScriptvisual FoxPro Accessible access to Class and Projects (Visual J # / JScript / C / Visual Basic) or Module (Visual Basic)
Public
public
public
public
public
NEW PUBLIC is accessible outside the class, but injects within the project (C #, Visual Basic, C ) or package (Visual J #, JScript)
Friend
(Omitted the scope of keyword will specify "package range") Public private:
Internal
Internal
New N / A is only available within the class (Visual J # / JScript / C / Visual Basic) or module (Visual Basic)
Private
Private
Private
Private
Private
New Hidden can only be accessed by current class and derived class
Protected
New protected
protected
protected
protected
New protected specifies a function or another class to access the private member N / A / A of the declaration class
Friend
(Not allowed in C hosted extensions) N / an / APA is protected in the program set, which is private n / an / APROTECTED Private: (only for c hosted exclusive) n / AN / A / A
Miscellaneous survival
Purpose Visual BasicVisual J # C C # New JScriptvisual FoxPro retention process local variable
Static
11static
Static
N / A / APRIVATE shared by all instances of a class
Shared
New static
Static
Static
Static
New N / A
Miscellaneous
Destination Visual BasicVisual J # C C # New JScriptvisual FoxPro Note Code
'
REM
// / ** * / / * * /
//, / * * / for multi-line comments
//, / * * / for multi-line comments
// Used for XML comments
//, / * * / for multi-line comments
*; &&case sensitive? No Yes Whether to call the Windows API
Declare
Call N / A using J / Direct or platform
Use platform calls
N / adeclare - DLL declaration and an event
Event
,
Raiseevent
Use a java.awt.event class or / ** @Event * / N / a
Event
N / A / A thread primary
Synclock
SYNCHRONIZED
LOCK
N / A / A go to
Goto
N / a
goto
goto
N / A / a
1. STATIC can be used by itself to declare the variable (for example, Static X as long) is in the process.
2. In Visual Basic, the process using the SUB keyword declaration cannot return a value. If a process needs to return a value, you must declare it using the function keyword.
3. Do not resolve the ME when compiling, so it can be used as the return value of the attribute or method.
4. Still supporting the substr function, but it is no longer the preferred method of accessing characters in the string. Accessing a characterful way from a specific location in a string is to use parentheses. For example, if you want to access the tenth character in the string STR, use Str [10].
5. In Visual Basic, the constructor of the class derived from the .NET Framework system.Object is always named New.
6. The constructor is not allowed to be overloaded in JScript.
7. Typically, the code release in this method cannot be automatically released by the garbage collector.
8. In C , an abstract class contains at least one pure virtual member.
9. Note that there is no previous guide number used in Visual Basic. This feature is prone to confusion because the variable may be mistakenly considered attribute, and vice versa. It should also be noted that the WITH statement will generate low-efficiency code.
10. Do not reallocate arrays, and will not "grow". The JScript array (declared Array type) is always a sparse dynamic array. Notell arrays (declared as System.Array or Type []) is not a dynamic array.
11. In Visual Basic, the static partial variable of the non-shared class is stored in each class instance, rather than sharing a copy like in other languages. If a variable is used to declare a variable, the value of the variable remains in the value when the variable is lost and re-obtained.
See
Equivalent language | Using code examples Compare programming concepts in different languages | Comparison of operators in different languages | Comparison of data types in different languages | Comparison of controls and programmable objects in different languages and libraries
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