Beginner with c# 4

发表于:2011-12-08来源:作者:点击数: 标签:
1iexcl;pound;4 Ocirc;¤para;¨Ograve;aring;Agrave;àETH;Iacute;pound;¨Predefined typespound;copy; c#Igrave;ásup1;copy;Aacute;E uml ;Ograve;raquo;Iuml;micro;Aacute;ETH;Ocirc;¤para;¨Ograve;aring;Agrave;àETH;Iacute;iexcl;pound;Euml;üAtil

  1¡£4 Ô¤¶¨ÒåÀàÐÍ£¨Predefined types£©

  c#ÌṩÁËһϵÁÐÔ¤¶¨ÒåÀàÐÍ¡£ËüÃÇÓëc/c++Óв»ÉÙÏàËƵĵط½¡£Ô¤¶¨ÒåÒýÓÃÀàÐÍÓÐobjectºÍstring¡£

  objectÀàÐÍÊÇËùÓÐÆäËûÀàÐ͵Ļù´¡¡£

  Ô¤¶¨ÒåÀàÐÍ°üÀ¨·ûºÅÊý¡¢ÎÞ·ûºÅÊý¡¢¸¡µã¡¢²¼¶û¡¢×Ö·ûºÍÊ®½øÖÆÊý¡£·ûºÅÊýÓУºsbyte¡¢short¡¢

  intºÍlong£»ÎÞ·ûºÅÊýÓУºbyte¡¢ushort¡¢uintºÍulong£»¸¡µãÊýÓУºfloatºÍdouble¡£

  ²¼¶ûÀàÐ;ÍÏñÒ»¸ö¿ª¹Ø£¬Ö»ÓÐÁ½ÖÖ״̬£ºtrue»òfalse¡£c#¶Ô²¼¶ûµÄÒªÇó±Èc/c++Ñϸñ£¬ÓëjavaÀàËÆ¡£

  ÔÚc#ÖÐfalse²»µÈÓÚ0£¬trueÒ²²»µÈÓÚ1£»falseºÍtrue¶¼Êǵ¥¶À·ÖÀë³öÀ´µÄÒ»¸öÖµ¡£Ñ§¹ýc/c++µÄÍøÓÑ

  ¶¼ÖªµÀ£º*/

  int i = 0;

  if (i = 0) { // Bug: Ó¦¸ÃÊÇ (i == 0)

  ....

  }

  /* ÊÇûÓÐÎÊÌâµÄ¡£µ«ÔÚc#ÖлáÒý·¢Ò»¸ö±àÒë´íÎó£¨error CS0029: Cannot implicitly convert

  type @#int@# to @#bool@#£©¡£µ±È»£¬ÕâÑùÎþÉüÁËÒ»µãûÓбØÒªµÄÁé»îÐÔ¡£ÎÒÃÇÔÙÒ²²»ÄÜÕâÑù£º*/

  string str;

  ....

  if(str = Console.ReadLine()) {

  Console.WriteLine("Your comments are: {0}",str);

  ....

  /* ¶ø±ØÐ룺*/

  using System;

  class BoolTest

  {

  static void Main() {

  string str = Console.ReadLine();//Ò²¿ÉÒÔ£ºstring str;

  if(str == "") // if((str = Console.ReadLine()) == "")

  Console.WriteLine("i can@#t read your comments. Please tell me something! O.K.?");

  else

  Console.WriteLine("Your comments are: {0}",str);

  }

  }

  /*

  ÎÒ³­ÁËÒ»ÕÅÔ¤¶¨ÒåÀàÐ͵ļò±í¹©´ó¼Ò²Î¿¼¡£

  Type Description Examples

  object The ultimate base type of all other types object o = new Stack();

  string String type; a string is a sequence of string s = "Hello";

  Unicode characters

  sbyte 8-bit signed integral type sbyte val = 12;

  short 16-bit signed integral type short val = 12;

  int 32-bit signed integral type int val = 12;

  long 64-bit signed integral type long val1 = 12;

  long val2 = 34L;

  byte 8-bit unsigned integral type byte val1 = 12;

  byte val2 = 34U;

  ushort 16-bit unsigned integral type ushort val1 = 12;

  ushort val2 = 34U;

  uint 32-bit unsigned integral type uint val1 = 12;

  uint val2 = 34U;

  ulong 64-bit unsigned integral type ulong val1 = 12;

  ulong val2 = 34U;

  ulong val3 = 56L;

  ulong val4 = 78UL;

  float Single-precision floating point type float value = 1.23F;

  double Double-precision floating point type double val1 = 1.23

  double val2 = 4.56D;

  bool Boolean type; a bool value is either bool value = true;

  true or false

  char Character type; a char value is a Unicode char value = @#h@#;

  character

  decimal Precise decimal type with 28 significant digits decimal value = 1.23M;

  ÄãÒ²¿ÉÒÔ×Ô¶¨Òå×Ô¼ºµÄÔ¤¶¨ÒåÀàÐÍ£¬¿ÉÒÔÕâÑù£º*/

  using System;

  struct Digit

  {...}

  class Test

  {

  static void TestInt() {

  int a = 1;

  int b = 2;

  int c = a + b;

  Console.WriteLine(c);

  }

  static void TestDigit() {

  Digit a = (Digit) 1;

  Digit b = (Digit) 2;

  Digit c = a + b;

  Console.WriteLine(c);

  }

  static void Main() {

  TestInt();

  TestDigit();

  }

  }

  /*

  ÕâÒ»½ÚÓеã³ÁÃÆ¡££º£¨

原文转自:http://www.ltesting.net

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