C和指针之字符操作(＜ctype.h＞)

   

    

     

      

     
     

      

       #include <stdio.h>
      
     
    

     

      

     
     

      

       #include <ctype.h>
      
     
    

     

      

     
     

      
 
      
     
    

     

      

     
     

      

       int main()
      
     
    

     

      

     
     

      

       {
      
     
    

     

      

     
     

      

        //字符分类
      
     
    

     

      

     
     

      

        char a = 'A';
      
     
    

     

      

     
     

      

        printf("islower(%c) is %d\n", a, islower(a));
      
     
    

     

      

     
     

      

        char b = 'B';
      
     
    

     

      

     
     

      

        printf("isupper(%c) is %d\n", b, isupper(b));
      
     
    

     

      

     
     

      

        char c = 'C';
      
     
    

     

      

     
     

      

        //是不是字母
      
     
    

     

      

     
     

      

        printf("isalpha(%c) is %d\n", c, isalpha(c));
      
     
    

     

      

     
     

      
 
      
     
    

     

      

     
     

      

        //字符转换
      
     
    

     

      

     
     

      

        char d = 'D';
      
     
    

     

      

     
     

      

        printf("tolower(%c) is %c\n", d, tolower(d));
      
     
    

     

      

     
     

      

        char e = 'e';
      
     
    

     

      

     
     

      

        printf("toupper(%c) is %c\n", e, toupper(c)