2. constºÍreadonlyÓÐʲôÇø±ð£¿
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6. structºÍclassÓÐʲôÇø±ð
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7. tryºóÃæÒ»¸öfinally£¬tryÖÐÓÐÒ»¸öreturn£¬ÄÇôfinallyÖеĴúÂë»á²»»áÔËÐУ¿Èç¹ûÔËÐУ¬ÊÇÔÚreturnºó»¹ÊÇreturnÇ°¡£
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8. ²úÉúÒ»¸öintÊý×飬³¤¶ÈΪ100£¬²¢ÏòÆäÖÐËæ»ú²åÈë1-100£¬²¢ÇÒ²»ÄÜÖظ´¡£
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int[] array = new int[100];
int temp[] = new int[100];
for (int i = 0; i < 100; i++)
{
temp[i]=i+1;
}
Random rand = new Random();
for (int i = 0; i < 100; i++)
{
int index = rand.Next(100-i-1);
array[i] = temp[index];
temp[index]=temp[100-i-1];
}
9. C#ÖÐҪʹһ¸öÀàÖ§³Öforeach±éÀú£¬ÊµÏÖ¹ý³ÌÔõÑù£¿
´ð£º±ØÐëʵÏÖIEnumerable,IEnumeratorÕâÁ½¸ö½Ó¿Ú£¬ÈçÏ£º
public class MyList : IEnumerable,IEnumerator
{
private int position = -1;
string[] array = new string[4];
public MyList()
{
array[0] = "a";
array[1] = "b";
array[2] = "c";
array[3] = "d";
}
#region IEnumerable ³ÉÔ±
//ÿ´ÎʹÓÃforeachʱ¶¼»áµ÷ÓÃËüµÃµ½Ò»¸öö¾ÙÆ÷
public IEnumerator GetEnumerator()
{
Reset();
return (this as IEnumerator);
}
#endregion
#region IEnumerator ³ÉÔ±
//±éÀúʱͨ¹ýÕâ¸öÊôÐԵõ½Öµ
public object Current
{
get { return array[position]; }
}
//·ÃÎÊÏÂÒ»¸öÔªËØʱʹÓÃMoveNextÒƶ¯Î»ÖÃ
public bool MoveNext()
{
if (position < array.Length-1)
{
position++;
return true;
}
else
return false;
}
//±éÀúǰҪʹλÖùéλ
public void Reset()
{
position = -1;
}
#endregion
}
ÒÔϲ»ÓÃforeach±éÀú¼¯ºÏ
MyList list=new MyList();
While(list.MoveNext())
{
Object o=list.Current;
}
10. ÒÔϳÌÐòÓÐʲô´í£¿
public class TestClass
{
private int count;
private static int y;
public static void setvalue £¨£©
{
count=1;
y=1;
}
}
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11. netÖÐʲôÀ಻Äܱ»¼Ì³Ð£¿
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sealed ³ýÁË¿ÉÒÔÓ¦ÓÃÓÚÀàÍ⣬»¹¿ÉÒÔÓ¦ÓÃÓÚʵÀý·½·¨ºÍÊôÐÔ¡£ÃÜ·â·½·¨»áÖØд»ùÀàÖеķ½·¨£¬µ«Æä±¾Éí²»ÄÜÔÚÈκÎÅÉÉúÀàÖнøÒ»²½ÖØд¡£µ±Ó¦ÓÃÓÚ·½·¨»òÊôÐÔʱ£¬sealed ÐÞÊηû±ØÐëʼÖÕÓëoverrideÒ»ÆðʹÓá£È磺
//ÏÂÃæÕâ¸ösealedʹÓÃÕýÈ·£¬±íʾ¸ÃÀ಻Äܼ̳Ð
public sealed class Test
{
private int myVar;
//ÏÂÃæÕâ¸ösealed´íÎ󣬱àÒë²»»áͨ¹ý£¬ÒòΪsealed±ØÐëºÍoverrideÒ»ÆðʹÓÃ
public sealed int MyProperty
{
get { return myVar; }
set { myVar = value; }
}
//ÏÂÃæÕâ¸ösealedʹÓÃÕýÈ·£¬±íʾÈç¹û¸ÃÀ಻ÊÇÃÜ·âÀ࣬
//ÄÇôÔÚÅÉÉúÀàÖÐÒ²²»¿ÉÒÔÖØд¸Ã·½·¨
public sealed override string ToString()
{
return base.ToString();
}
}
12. is ºÍas ÓÐʲôÇø±ð£¿
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Dog d=new Dog();
If(d is Dog)
{
Console.WriteLine(¡°dÊÇÒ»Ö»¹·¡±);
}
ÒÔÉÏÓï¾äConsole.WriteLine(¡°dÊÇÒ»Ö»¹·¡±);»áÔËÐУ¬ÒòΪd is Dog·µ»Øtrue,Èç¹ûDog´ÓAnimalÀà¼Ì³Ð²¢ÊµÏÖÁËIPet½Ó¿Ú,Ôòd is AnimalºÍd is IPet¶¼»á·µ»Øtrue;
asÓÃÓÚÔÚ¼æÈݵÄÒýÓÃÀàÐÍÖ®¼äÖ´ÐÐת»»,Èç¹ûת»»Ê§°ÜÔò·µ»Ønull,ËüµÈ¼ÛÓÚÈçÏÂÓï¾ä£º
expression is type (type)expression : (type)null
13. netÖк¯Êý´«µÝ²ÎÊýÓÐÄÇЩ·½Ê½£¿ÓÐʲôÇø±ð£¿
´ð£º´«ÖµºÍ´«ÒýÓ㬴«ÒýÓÃÓÖÁ½ÖÖ·½Ê½£¬refºÍout£¬refÒªÇó±äÁ¿ÔÚ´«²ÎÇ°¸³Öµ£¬out¿ÉÒÔ²»¸³Öµ¡£´«ÒýÓñØÐëÊÇÒ»¸öµØÖ·£¬´«ÖµÊÇÖ¸½«Õ»ÖеÄÖµ¿½±´µ½º¯ÊýµÄ²ÎÊý£¬´«ÒýÓñíʾ´«ÈëµÄ±äÁ¿ºÍ½ÓÊÕ²ÎÊýÊÇͬһ¸ö±äÁ¿
public class Test
{
public int myVar;
public int MyProperty
{
get { return myVar; }
set { myVar = value; }
}
}
ÒÔÉÏÕâ¸öÀàÖÐÓÐ×ֶκÍÊôÐÔ
private void F(ref int i)
{
i = 100;
}
ÓÐÒ»¸ö·½·¨´«µÝÒýÓ㬵÷Ó÷½Ê½ÈçÏ£º
Test t = new Test();
F(ref t. MyProperty);
ÒÔÉÏ´úÂë±àÒë²»ÄÜͨ¹ý£¬ÒòΪÊôÐÔ²»ÊDZäÁ¿£¬ÆäʵÖÊÊǺ¯Êý£¬ÈçÏÂÔò¿Éͨ¹ý
Test t = new Test();
F(ref t. myVar);
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14. Ò»ÁÐÊýµÄ¹æÔòÈçÏÂ: 1¡¢1¡¢2¡¢3¡¢5¡¢8¡¢13¡¢21¡¢34...... ÇóµÚ30λÊýÊǶàÉÙ£¬ ÓõݹéË㷨ʵÏÖ¡£
´ð£ºpublic class MainClass
{
public static void Main()
{
Console.WriteLine(Foo(30));
}
public static int Foo(int i)
{
i