程序設計基礎(C)第03講例程

3.1 platinum.c

/* platinum.c  -- your weight in platinum */
#include <stdio.h>
int main(void)
{
    float weight;    /* 你的體重             */
    float value;     /* 相等重量的白金價值     */
    
    printf("Are you worth your weight in platinum?\n");
    printf("Let's check it out.\n");
    printf("Please enter your weight in pounds: ");
    
    /* 獲取用戶的輸入                     */
    scanf("%f", &weight);
    /* 假設白金的價格是每盎司$1700          */
    /* 14.5833  用於將英鎊常衡盎司轉換爲金衡盎司	```*/
    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");
    
    return 0;
}

3.2 print1.c

/* 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 );  // 錯誤，遺漏了兩個參數
    
    return 0;
}

3.3 bases.c

/* bases.c--以十進制、八進制、十六進制打印十進制數100*/
#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);
    
    return 0;
}

3.4 print2.c程序

/* print2.c-更多printf() 特性 */
#include <stdio.h>
int main(void)
{
    unsigned int un = 3000000000; /* int爲32位的系統 */
    short end = 200;              /* short爲16位的系統 */
    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);
    
    return 0;
}

3.5 charcode.c

/* charcode.c-顯示字符的代碼編號 */
#include <stdio.h>
int main(void)
{
    char ch;
    
    printf("Please enter a character.\n");
    scanf("%c", &ch);   /* 用戶輸入字符 */
    printf("The code for %c is %d.\n", ch, ch);
    
    return 0;
}

3.6 altnames.c

/* altnames.c --  可移植整數類型名 */
#include <stdio.h>
#include <inttypes.h> // 支持可移植類型
int main(void)
{
    int32_t me32;     // me32 是一個32位有符號整型變量
    
    me32 = 45933945;
    printf("First, assume int32_t is int: ");
    printf("me32 = %d\n", me32);
    printf("Next, let's not make any assumptions.\n");
    printf("Instead, use a \"macro\" from inttypes.h: ");
    printf("me32 = %" PRId32 "\n", me32);
    
    return 0;
}

3.7showf_pt.c

/* showf_pt.c -- 以兩種方式顯示float類型的值 */
#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);
    //下一行要求編譯器支持c99或其中的相關特性
    printf("And it's %a in hexadecimal, powers of 2 notation\n", aboat);
    printf("%f can be written %e\n", abet, abet);
    printf("%Lf can be written %Le\n", dip, dip);
    
    return 0;
}

3.8 typesize.c

//* typesize.c -- 打印類型大小爲類型大小提供%zd的轉換說明 */
#include <stdio.h>
int main(void)
{
    /* c99爲類型大小提供%zd的轉換說明 */
    printf("Type int has a size of %zd bytes.\n", sizeof(int));
    printf("Type char has a size of %zd bytes.\n", sizeof(char));
    printf("Type long has a size of %zd bytes.\n", sizeof(long));
    printf("Type long long has a size of %zd bytes.\n",sizeof(long long));
    printf("Type double has a size of %zd bytes.\n",sizeof(double));
    printf("Type long double has a size of %zd bytes.\n",sizeof(long double));
    return 0;
}

3.10 escape.c

/* escape.c -- 使用轉義序列 */
#include <stdio.h>
int main(void)
{
    float salary;
    
    printf("\aEnter your desired monthly salary:");/* 1 */
    printf(" $_______\b\b\b\b\b\b\b");             /* 2 */
    scanf("%f", &salary);
    printf("\n\t$%.2f a month is $%.2f a year.", salary,salary * 12.0);                         /* 3 */
    printf("\rGee!\n");                            /* 4 */
    
    return 0;
}