1。4 Ô¤¶¨ÒåÀàÐÍ！redefined types）
c#Ìá¹�ÁËһϵÁÐÔ¤¶¨ÒåÀàÐÍ。ËüÃÇÓëc/c++Óв»ÉÙÏàËƵĵط½。Ô¤¶¨ÒåÒýÓÃÀàÐÍÓÐobjectºÍstring。
objectÀàÐÍÊÇËùÓÐÆäËûÀàÐ͵Ļù´ �
Ô¤¶¨ÒåÀàÐÍ°üÀ¨·ûºÅÊý、ÎÞ·ûºÅÊý、¸�µã、²¼¶û、×Ö·ûºÍÊ®½øÖÆÊý。·ûºÅÊýÓÐ�ºsbyte、short、
intºÍlong�»ÎÞ·ûºÅÊýÓÐ�ºbyte、ushort、uintºÍulong�»¸�µãÊýÓÐ�ºfloatºÍdouble。
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。ѧ¹ýc/c++µÄÍøÓÑ
¶¼ÖªµÀ�º*/
int i = 0;
if (i = 0) { // Bug: Ó¦¸ÃÊÇ (i == 0)
....
}
/* ÊÇûÓÐÎÊÌâµÄ。µ«ÔÚc#ÖлáÒý·�Ò»¸ö±àÒë´íÎó！rror 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±ØÐë�º*/
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&po