在C中使用不同的库

Question

我只是从头开始编写一个程序,它可以计算用户输入的大写和小写字母以及空格.从那时起,我发现这些特定函数的代码已经在另一个库中预先编写了!我的问题是,我在下面编写的所有代码如何通过使用来简化

isupper(int c),, islower(int c)和isspace(int c)哪些在中定义ctype.h.

#include <stdio.h>

int main(void){
int iochar, numdigits=0, numlower=0, numupper=0, numwhites=0;

printf("Please enter a phrase:\n\n");

while((iochar=getchar())!=EOF) 
{
    if ((iochar==' ')||(iochar=='\t')||(iochar=='\n'))
    {
        numwhites++;
        putchar(iochar);
    }
    else 
        if((iochar>='0')&&(iochar<='9')) 
        {
            numdigits++;
            putchar(iochar);
        }
        else 
            if(('a'<=iochar)&&(iochar<='z')) 
            {
                numlower++;
                putchar(iochar-32);
            } 
            else 
                if(('A'<=iochar)&&(iochar<='Z'))
                {
                    numupper++;
                    putchar(iochar);
                }
                else 
                    putchar(iochar);    
}

printf("%d white characters, %d digits, ",numwhites,numdigits);
printf("%d lowercase have been converted to ",numlower);
printf("uppercase and %d uppercase.\n",numupper);

printf("\n\n");


return 0;}

Answer 1

这是写得更好,清理得更好:

#include <stdio.h>
#include <ctype.h>

int main(int argc, char **argv) {
    int iochar, numdigits=0, numlower=0, numupper=0, numwhites=0;

    printf("Please enter a phrase:\n\n");

    while ((iochar=getchar()) != EOF) {
        // increase counts where necessary
        if (isspace(iochar)) {
            numwhites++;
        } else if (isdigit(iochar)) {
            numdigits++;
        } else if (islower(iochar)) {
            numlower++;
            iochar = toupper(iochar);
        } else if (isupper(iochar)) {
            numupper++;
        }

        // this happens always, don't put it in the if's
        putchar(iochar);
    }

    printf("%d white characters, %d digits, ", numwhites, numdigits);
    printf("%d lowercase have been converted to ", numlower);
    printf("uppercase and %d uppercase.\n", numupper);

    printf("\n\n");

    return 0;
}