经典练习程序代码.doc

#include iostream.h main() { //用SIZEOF计算常量长度 coutsizeof($)=sizeof($)endl; coutsizeof(1)=sizeof(1)endl; coutsizeof(1.5)sizeof(1.5)endl; coutsizeof(\Good!\)=sizeof(Good!)endl; //sizeof计算变量长度 int i=100; char c=A; float x=3.1416; double p=0.1; coutsizeof(i)=sizeof(i)endl; coutsizeof(c)=sizeof(c)endl; coutsizeof(x)=sizeof(x)endl; coutsizeof(p)=sizeof(p)endl; //用SIZEOF()计算表达式长度 coutsizeof(x+1.732)=sizeof(x+1.732)endl; // coutsizoef(char)=sizeof(char)endl; coutsizoef(int)=sizeof(int)endl; coutsizeof(float)=sizeof(float)endl; coutsizeof(double)=sizeof(double)endl; //用SIZEOF()算数组字节长 char str[]=This is a test; int a[10]; double xy[10]; coutsizeof(str)=sizeof(str)endl; coutsizeof(a)=sizeof(a)endl; coutsizeof(xy)=sizeof(xy)endl; //用SIZEOF 算自定类型字节长 struct st { short num; float math_grade; float Chinese_grade; float sum_grade; }; st student1; coutsizeof(st)=sizeof(st)endl; coutsizeof(student)=sizeof(student1)endl; } #include iostream.h main()//测试表达式类型转换 { int n=100,m; double x=3.791,y; coutn*x=n*xendl; //赋值类型转换 m=x; y=n; coutm=mendl; couty=yendl; //强制转换 coutint(x)=int(x)endl; cout(int)x=(int)xendl; coutint(1.732+x)=int(1.732+x)endl; cout(int)1.732=(int)1.732endl; coutdouble(100)=double(100)endl; //*/ } -----------==================------------------------ #include iostream.h main() { int score; coutscore=; cinscore; if(score0||score100) { coutThe score is out of range!endl; } else if(score=90) coutyou grage is a Aendl; else if(score=80) coutyou grade is a Bendl; else if(score=70) coutyou grade is a Cendl; else if(score=60) coutyou grade is a Dendl; else coutyou grade is a Eendl; } #include iostream.h main() { int x,y,z; char c1; cinxc1y; switch(c1) { case +:coutx+y=x+yendl; break; case -:coutx-y=x-yendl; break; case *:coutx*y=x*yendl; break; case /:coutx/y=x/yendl; break; case %:coutx%y=x%yendl; default:coutWrong !endl; } } ---------------------------=========