main()
{
    printf("I love music!\n");
    printf("the music is \"D:\\music\\love.mp3\".\n");

}

#include "stdio.h"
#define PI 3.14                      //符号常量  
main()
{
    float r,area;                       //定义变量  
    r=1.5;                                //赋值 
    area=PI*r*r;                       //计算语句 
    printf("area=%f\n",area);   //输出结果 

}

main()
{
    int x,y,z;
    x=2;
    y=3;
    z=x+y;
    printf("x+y=%d\n",z);

}

main()
{
    float r=1.5,pi,area; 
    pi=3.14; 
    area=pi*r*r;
    printf("area=%f\n",area); 

}

main()
{

    int m;
    char c;
    m=‘A‘;    //字符赋值给整型变量 
    c=66;    //整数赋值给字符变量
    printf("%c,%d\n",m,m);
    printf("%c,%d\n",c,c);
}

main()
{
    int i=2; 
    float f=1.5;
    double d=4.0;
    long e=2;
    printf(“i*f=%f,i转化为float类型参与运算",i*f);
    printf(“d/e=%lf,e转化为double类型参与运算",d/e);
    printf("10+‘a‘=%d,‘a‘转化为int类型参与运算",10+‘a‘);
    printf("10+‘a‘+i*f=%f,int转化为float类型",10+‘a‘+i*f);
    printf("10+‘a‘+i*f-d/e=%lf,float转化为double类型",10+‘a‘+i*f-d/e); 

}

main()
{
    float f;
    f=9.8;
    printf("(int)f=%d,f=%f\n",(int)f,f);

}