vb.net和c#语法比较
2020-02-03 15:26:22
供稿：网友
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由于一些人对vb.net和c#选择方面存在一些困惑，其实只是语法习惯问题，我把它们的语法列出来比较一下，大家有个感性认识。
1.变量声名
c# 语法
int x;
string s;
string s1, s2;
object o;
object obj = new object();
public string name;
vb语法
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
2语句
c#:
response.write("中文c#技术站");
vb:
response.write("中文c#技术站")
3.注释语句
//中文c#技术站
/*
欢迎访问
，
中文c#技术站
*/
vb:
'中文c#技术站
4.获得url 传递的变量
c#:
string s = request.querystring["name"];
string value = request.cookies["key"];
vb:
dim s, value as string
s = request.querystring("name")
value = request.cookies("key").value
5.声明属性
c#:
public string name {
get {
...
return ...;
}
set {
... = value;
}
}
vb:
public property name as string
get
...
return ...;
end get
set
... = value;
end set
end property
6.数组
c#
string[] a = new string[3];
a[0] = "1";
a[1] = "2";
a[2] = "3";
//二维数组
string[][] a = new string[3][3];
a[0][0] = "1";
a[1][0] = "2";
a[2][0] = "3";
vb:
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"
dim a() as string
a(0,0) = "1"
a(1,0) = "2"
a(2,0) = "3"
dim a(,) as string
a(0,0) = "1"
a(1,0) = "2"
a(2,0) = "3"
7变量初始化
c#:
string s = "hello world";
int i = 1
double[] a = { 3.00, 4.00, 5.00 };
vb:
dim s as string = "hello world"
dim i as integer = 1
dim a() as double = { 3.00, 4.00, 5.00 }
8;判断语句(if 语句)
if (request.querystring != null) {
...
}
vb:
if not (request.querystring = null)
...
end if
9.分支语句(case 语句)
c#:
switch (firstname) {
case "john" :
...
break;
case "paul" :
...
break;
case "ringo" :
...
break;
}
vb:
select (firstname)
case "john" :
...
case "paul" :...
case "ringo" :
...
end select
10 for循环语句
c#
for (int i=0; i<3; i++)
a(i) = "test";
vb:
dim i as integer
for i = 0 to 2
a(i) = "test"
next
11 while 循环
c#:
int i = 0;
while (i<3) {
console.writeline(i.tostring());
i += 1;
}
vb:
dim i as integer
i = 0
do while i < 3
console.writeline(i.tostring())
i = i + 1
loop
12 字符串连接
c#:
string s1;
string s2 = "hello";
s2 += " world";
s1 = s2 + " !!!";
vb:
dim s1, s2 as string
s2 = "hello"
s2 &= " world"
s1 = s2 & " !!!"
声明事件
c#:
void mybutton_click(object sender,
eventargs e) {
...
}
vb:
sub mybutton_click(sender as object,
e as eventargs)
...
end sub
13 声明object
c#
myobject obj = (myobject)session["some value"];
imyobject iobj = obj
vb:
dim bj as myobject
dim iobj as imyobject
obj = session("some value")
iobj = ctype(obj, imyobject)
14 数据类型转换
c#
int i = 3;
string s = i.tostring();
double d = double.parse(s);
vb:
dim i as integer
dim s as string
dim d as double
i = 3
s = i.tostring()
d = cdbl(s)
15 类的声明和继承
c#:
using system;
namespace myspace {
public class foo : bar {
int x;
public foo() { x = 4; }
public void add(int x) { this.x += x; }
public int getnum() { return x; }
}
}
vb:
imports system
namespace myspace
public class foo : inherits bar
dim x as integer
public sub new()
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
16 声明类的主函数
c#:
using system;
public class consolecs {
public consolecs() {
console.writeline("object created");
}
public static void main (string[] args) {
console.writeline("hello world");
consolecs ccs = new consolecs();
}
}
vb
imports system
public class consolevb
public sub new()
mybase.new()
console.writeline("object created")
end sub
public shared sub main()
console.writeline("hello world")
dim cvb as consolevb
cvb = new consolevb()
end sub
end class
17 标准模块
c#
using system;
public class module {
public static void main (string[] args) {
console.writeline("hello world");
}
}
vb:
imports system
public module consolevb
public sub main()
console.writeline("hello world")
end sub
end module
