Pascal、VB、C#、Java四种语法对照表

Pascal、VB、C#、Java四种语法对照表

ASP.NET支持的几种语言：c#.net，vb.net，delphi.net(非内置支持)，由于在.net框架下，所有的语言均使用同一个类库，因此功能上是基本上一模一样，只语法上各不相同。

.net与java为两大阵营，为了比较，在此列出一个简单的语法对照表，看看你到底喜欢那个？

 

类别	delphi.net语法	vb.net 语法(语法不区分大小写)	c#.net 语法	java
语法	不区分大小写	不区分大小写	区分大小写	区分大小写
定义变量	Var x: Integer; s: string; s1, s2: string; o: TObject; obj: TObject; obj := TObject.Create; Public property name: String;	Dim x As Integer Dim s As String Dim s1, s2 As String Dim o 'Implicitly Object Dim obj As New Object() Public name As String	int x; String s; String s1, s2;　　　　　　 Object o; Object obj = new Object(); public String name;	int x; String s; String s1, s2;　　　　　　 Object o; Object obj = new Object(); public String name;
输出内容	Response.write(‘foo’);	Response.Write("foo")	Response.Write("foo");	Response.Write("foo");
注释	// This is a comment　　　　　 /* This is a  multi-line  comment */	' This is a comment ' This is a ' multi-line ' comment	// This is a comment /* This is a  multi-line  comment */	// This is a comment /* This is a  multi-line  comment */
读取数据集合数组	var s, value: String begin s := Request.QueryString[‘Name’]; Value := Request.Cookies(‘Key’).Value; end;	Dim s as String = Request.QueryString("Name") Dim value As String = Request.Cookies("Key")	String s=Request.QueryString["Name"]; String value=Request.Cookies["key"];	String s = request.getParameter("Name"); String value; Cookie ck = null; Cookie args[] = Request.getCookies(); for(int i = 0; i<args.length; i++){     ck = args[i];    if(ck.getName().equals("key "))         value = ck.getValue(); }
字符串操作	var s1, s2: String; begin s2 := ‘hello’; s2 := s2 + ‘world’; s1 := s2 + ‘!!!’; End;	Dim s1, s2 As String  s2 = "hello"  s2 &= " world"  s1 = s2 & " !!!"	String s1;  String s2 = "hello";  s2 += " world";  s1 = s2 + " !!!";	String s1;  String s2 = "hello";  s2 += " world";  s1 = s2 + " !!!";

 

 

 

 

 

类别	delphi.net语法	vb.net 语法(语法不区分大小写)	c#.net 语法	java
初始化变量	var s: String; I: Integer; A: array of double = {3.00, 4.00, 5.00}	Dim s As String = "Hello World"  Dim i As Integer = 1  Dim a() As Double = { 3.00, 4.00, 5.00 }	String s = "Hello World";  int i = 1  double[] a = { 3.00, 4.00, 5.00 };	String s = "Hello World";  int i = 1  double[] a = new double[]{ 3.00, 4.00, 5.00 };
定义简单数据集	Public Record Name: String;   Function GetName: String; Begin   ...;   Result := …; End;   Procedure SetName(Value: String); Begin   … := Value; End;   End	Public Property Name As String   Get  ...  Return ...;  End Get Set ... = Value;  End Set End Property	public String name {  get{ ...  return ...;  } set{ ... = value;  } }	private String name;   public String getName(){ return name; }   public void setName(String name){ this.name = name; }
数组	var a[0..2]: string a[0..2,0..2]: String begin a[0] := ‘1’; a[1] := ‘2’; a[2] := ‘3’; a[0,0] := ‘1’; a[1,0] := ‘2’; a[2,0] := ‘3’; End;	Dim a(3) As String  a(0) = "1"  a(1) = "2"  a(2) = "3"  Dim a(3,3) As String  a(0,0) = "1"  a(1,0) = "2"  a(2,0) = "3"	String[] a = new String[3];  a[0] = "1";  a[1] = "2";  a[2] = "3”; String[][] a = new String[3][3];  a[0][0] = "1";  a[1][0] = "2";  a[2][0] = "3";	String[] a = new String[3]; a[0] = "1"; a[1] = "2"; a[2] = "3"; String[][] a = new String[3][3]; a[0][0] = "1"; a[1][0] = "2"; a[2][0] = "3";
对象操作	var bj: MyObject; iObj: IMyObject; begin obj := Session(‘Some Value’); iObj = Obj as IMyObject; end;	Dim bj As MyObject = Session("Some Value") Dim iObj As IMyObject = CType(obj, IMyObject)	MyObject obj = (MyObject)Session["Some Value"]; IMyObject iObj = obj;	MyObject obj = (MyObject)Session.getItem ("Some Value"); IMyObject iObj = obj;
类型转换	var i: Integer; s: String; d: Double; begin i := 3; s = i.ToString(); d := Double.Parse(s); end;	Dim i As Integer = 3 Dim s As String = i.ToString() Dim d As Double = Double.Parse(s):	int i = 3;  String s = i.ToString();  double d = Double.Parse(s);	int i = 3;  String s = Integer.valueof(i).toString(); double d = Double.valueof(s);

 

 

 

 

类别	delphi.net语法	vb.net 语法(语法不区分大小写)	c#.net 语法	java
If 结构	If Not (Request.QueryString = Null) then begin ... End;	If Not (Request.QueryString = Null)  ...  End If	if (Request.QueryString != null) { ...  }	if (Request.QueryString != null) { ...  }
Case结构	Case FirstName of ‘John’: ... ‘Paul’: … ‘Ringo’: … End	Select (FirstName) case "John" : ...  case "Paul" : ... case "Ringo" : ... End Select	switch (FirstName){ case "John" :   ...    break;  case "Paul" :    ...    break;  case "Ringo" :    ...   break;  }	int flag = 1; switch (flag){ case 1:     ...         break; case 2:     ...         break; }
For循环	Var I: Integer; Begin For I := 0 to 2 do A[i] := ‘test’; End;	Dim I As Integer For I = 0 To 2 　a(I) = "test" Next	for (int i=0; i<3; i++)  a(i) = "test";	for (int i=0; i<3; i++)  a[i] = "test";
While循环	Var I: Integer; Begin I := 0; While i< 3 do Begin Console.WriteLen(i.ToString()); I := I + 1; End; End;	Dim I As Integer I = 0 Do While I < 3 Console.WriteLine(i.ToString()); I = I + 1 Loop	int i = 0;  while (i<3) { Console.WriteLine(i.ToString()); i += 1; }	int i = 0;  while (i<3) { System.out.println(i); i += 1; }

 

 

 

 

类别	delphi.net语法	vb.net 语法(语法不区分大小写)	c#.net 语法	java
类定义和继承	unit MySpace interface uses  System;   type   Foo = Class(Bar)   private     x: integer;   public     procedure Create; override; //构造函数     procedure Add(x: Integer);     function GetNum: Integer;   end;   implementation procedure Foo.Create; begin   inherited;  x := 4; end;   procedure Foo.Add(x: Integer); begin Self.x := Self.x + x; end;   function Foo.GetNum: Integer; begin Result := x; end;   end;	Imports System   Namespace MySpace Public Class Foo : Inherits Bar  Dim x As Integer  Public Sub New() ‘构造函数   MyBase.New()    x = 4  End Sub Public Sub Add(x As Integer)    Me.x = Me.x + x  End Sub Public Function GetNum() As Integer    Return x  End Function End Class End Namespace  ' vbc /out:libraryvb.dll /t:library library.vb	using System; namespace MySpace { public class Foo : Bar { int x;   public Foo() {x = 4; } //构造函数 public void Add(int x) { this.x += x; }  public int GetNum() { return x; }  } } // csc /out:librarycs.dll /t:library library.cs	import java.lang.*;   package MySpace;   public class Foo extends Bar{   private int x; //私有变量   public Foo() {x = 4; } //构造函数 public void Add(int x) { this.x += x; } //过程 public int getNum() { return x; } //函数 }
事件处理	procedure Button1OnClick(Sender: Object;E: EventArgs); begin ... end; ‘ByRef 在Pascal中对象是缺省参数传递方式	Sub Button1_Click(Sender As Object, E As EventArgs) ...  End Sub ‘ByVal 在VB中对象是是缺省参数传递方式	void Button1_Click(Object sender, EventArgs E) { ...  }　 ‘ByRef 在C#中对象是是缺省参数传递方式	jButton1.addMouseListener(new java.awt.event.MouseAdapter() { public void mouseClicked(java.awt.event .MouseEvent evt) { Button1_Click(evt); } });   private void Button1_Click(java.awt. event .MouseEvent evt) { }