069_ctype库函数的使用-1

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我是靠谱客的博主无限悟空，这篇文章主要介绍069_ctype库函数的使用-1，现在分享给大家，希望可以做个参考。

判断一个字符是否是十进制数组

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#include "stdio.h"
#include "ctype.h"

unsigned char s[] = "1234567890abc";

int main(void)
{
    int i = 0;

    while(s[i] != '')
    {
        if(isdigit(s[i]))
        {
            printf("%c is a num.n",s[i]);
        }
        else
        {
            printf("%c is not a num.n",s[i]);
        }

        i++;
    }

    printf("%dn",sizeof(s));

    return 0;
}

执行结果：

.是否是字母测试

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void isalpha_test(void)
{
    unsigned char s[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz123!@'";
    int i = 0;

    while(s[i] != '')
    {
        if(isalpha(s[i]))
        {
            printf("%c is a alpha.n",s[i]);
        }
        else
        {
            printf("%c is a not alpha.n",s[i]);
        }
        i++;
    }
    
}

测试结果：

数字以及字母检测

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void isalnum_test(void)
{
    unsigned char s[] = "abcDFG1230x88_+-";
    int i = 0;

    while(s[i] != '')
    {
        if(isalnum(s[i]))
        {
            printf("%c is alnum.n",s[i]);
        }
        else
        {
            printf("%c is not alnum.n",s[i]);
        }
        i++;
    }
}