《C Primer Plus》第三章代码清单

//程序清单3.1
#include<stdio.h>
int main(void)
{
    float weight;
    float value;

    printf("Are you worth your weight in platinum?\n");
    printf("Let's check it out.\n");
    printf("Please enter your weight in pounds:");

    scanf("%f",&weight);

    value=1700.0*weight*14.5833;
    printf("Your weight in platinum is worth $%.2f.\n",value);
    printf("You are easily worth that!If platinum prices drop.\n");
    printf("eat more to maintain your value.\n");

    getchar();
    getchar();
    return 0;
}

//代码清单3.2 print1.c——演示printf()的一些特性
#include<stdio.h>
int main(void)
{
    int ten=10;
    int two=2;

    printf("Doing it right:");
    printf("%d minus %d is %d\n",ten,2,ten-two);
    printf("Doing it wrong:");
    printf("%d minus %d is %d\n",ten); //forgot 2 arguments

    getchar();
    return 0;
}

//代码清单3.3 bases.c——prints 100 in decimal,octal,and hex
#include<stdio.h>
int main(void)
{
    int x=100;

    printf("dec = %d;octal = %o;hex=%x\n",x,x,x);
    printf("dec = %d;octal = %#o;hex = %#x\n",x,x,x);

    getchar();
    return 0;
}

/*toobig.c——超出系统允许的最大值*/
#include<stdio.h>
int main(void)
{
    int i=2147483647;
    unsigned int j=4294967295;

    printf("%d %d %d\n",i,i+1,i+2);
    printf("%u %u %u\n",j,j+1,j+2);

    getchar();
    return 0;
}

/*代码清单3.4 print2.c——更多的printf()的特性*/
#include<stdio.h>
int main(void)
{
    unsigned int un=3000000000;
    short end=200;
    long big=65537;
    long long verybig=12345678908642;

    printf("un = %u and not %d\n",un,un);
    printf("end = %hd and %d\n",end,end);
    printf("big = %ld and not %hd\n",big,big);
    printf("verybig = %lld and not %ld\n",verybig,verybig);

    getchar();
    return 0;
}

/*代码清单3.5 charcode.c——显示字符的代码编号*/
#include<stdio.h>
int main(void)
{
    char ch;

    printf("Please enter a character.\n");
    scanf("%c",&ch);
    printf("The code for %c is %d.\n",ch,ch);

    getchar();
    getchar();
    return 0;
}

/*代码清单3.7 show_pt.c——以两种方式显示float类型的值*/
#include<stdio.h>
int main(void)
{
     float aboat=32000.0;
     double abet=2.14e9;
     long double dip=5.32e-5;

    printf("%f can be written %e\n",aboat,aboat);
    //下一行要求编译器支持C99或其中相关特性
    printf("And it's %a in hexadecimal,power of 2 notation\n",aboat);
    printf("%f can be written %e\n",abet,abet);
    printf("%Lf can be written %Le\n",dip,dip);
    getchar();
    return 0;
}

/* floaterr.c——演示舍入错误*/
#include<stdio.h>
int main(void)
{
    float a,b;

    b=2.0e20 + 1.0;
    a=b-2.0e20;
    printf("%f \n",a);

    getchar();
    return 0;
}

//程序清单3.8 typesize.c程序——打印类型大小
#include<stdio.h>
int main(void)
{
    printf("Type int has a size of %u bytes.\n",sizeof(int));
    printf("Type char has a size of %u bytes.\n",sizeof(char));
    printf("Type long has a size of %u bytes.\n",sizeof(long));
    printf("Type long long has a size of %u bytes.\n",sizeof(long long));
    printf("Type double has a size of %u bytes.\n",sizeof(double));
    printf("Type long double has a size of %lu bytes.\n",sizeof(long double));

    getchar();
    return 0;
}

//程序清单3.10  escape.c程序——使用转义序列
#include<stdio.h>
int main(void)
{
    float salary;

    printf("\aEnter your desired monthly salary");
    printf("$_______\b\b\b\b\b\b\b");
    scanf("%f",&salary);
    printf("\n\t$%.2f a month is $%.2f year.",salary,salary*12.0);
    printf("\rGee!\n");

    getchar();
    getchar();
    return 0;
}