C # key Knowledge (i) (turn)

Detailed in Microsoft's. NET launched, about C # related articles have appeared, as Microsoft's important and Java to contend with the language, C # has many advantages. This article will select some of the important knowledge in the C # language in detail,

The first chapter: parameter

1. 1 in Parameter

Four kinds of parameter forms of C # species:
General parameters
In Parameter
Out parameters
Parameter series
This chapter will introduce the following three kinds of use.

In the C language, you can pass the address (that is, the argument) or the Delphi language through the Var indicator to pass address parameters to the data ordering operations, in the C # language, how to do it? The "in" keyword can help you. This keyword can pass the value you want to return by using the parameter.
Namespace TESTREFP
{
Using System;
public class MyClass
{

public static void Reftest (ref int iVal1)
{
IVal1 + 2;

}
public static void Main ()
{
int i=3; Variable needs to be initialized

Reftest (ref i);
Console.WriteLine (i);

}
}
}

It is important to note that variables need to be initialized first.

Results:

5



1. 2 Out parameters


Do you want to return more than one value at a time? in the C + + language This task is basically impossible to accomplish. The "Out" keyword in C # can help you do it easily. This keyword can return more than one value at a time by a parameter.
public class MathClass
{
public static int testout (out int iVal1, out int iVal2)
{
IVal1 = 10;
IVal2 = 20;
return 0;
}

public static void Main ()
{
int I, J; The variable does not need to be initialized.
Console.WriteLine (Testout (out I, out J));
Console.WriteLine (i);
Console.WriteLine (j);
}
}

Results:

0 10 20

1. 3 Parameter Series

The parameter series can make a number of related parameters represented by a single sequence, in other words, the parameter series is the length of the variable.

Using System;

Class Test
{
static void F (params int[] args) {
Console.WriteLine ("# parameter: {0}", args.) Length);
for (int i = 0; i < args. Length; i++)
Console.WriteLine ("\targs[{0}] = {1}", I, args[i]);
}

static void Main () {
F ();
F (1);
F (1, 2);
F (1, 2, 3);
F (New int[] {1, 2, 3, 4});
}
}

The following are the output results:

# Parameters: 0
# Parameters: 1
Args[0] = 1
# Parameters: 2
Args[0] = 1
ARGS[1] = 2
# Parameters: 3
Args[0] = 1
ARGS[1] = 2
ARGS[2] = 3
# Parameters: 4
Args[0] = 1
ARGS[1] = 2
ARGS[2] = 3
ARGS[3]