指针句子大小写（C）

Question

I have problem to output text in sentence case characters. When I prompt: heLLo! heLLo. i am OKAY.

I'm expecting output: Hello! Hello. I am okay.

But my sample run output is: Hello! hello. i am okay.

My code cannot output uppercase after '!'/'.'/'?'/'_' Anybody can advise what mistake that I made? Thanks in advance.

-Ellie

Sample code:

printf ("\n\nThe line of the text in sentence case is:\n");

i = 0;
text_ptr = text;
up = 1;                 /* up = 1 means upper case is yes */
while ( *(text_ptr+i) != '\0')  /* could have been: while(text[i]) */
{
    if(!up)
        if( *(text_ptr+i-1)==' ' && toupper(*(text_ptr+i)=='I' && (*(text_ptr+i+1)==' ' ||
                *(text_ptr+i+1)=='.' || *(text_ptr+i+1)=='!' || *(text_ptr+i+1))=='?') )
        up = 1;     /* capitalize i if all alone */

    if(up)
        if (*(text_ptr+i)!=' ' || *(text_ptr+i+1)=='.' || *(text_ptr+i+1)=='!' || *(text_ptr+i+1)=='?')
        {
            putchar(toupper(*(text_ptr++)));
            up = 0;
        } /* end if */
        else
            putchar(tolower(*(text_ptr++)));
    else
    {
        putchar(tolower(*(text_ptr+i)));
        if (*(text_ptr)=='?' || *(text_ptr)=='.' || *(text_ptr)=='!')
            up = 1;
        i++;
    } /* end else */
}/* end while */`

Answer 1

Once again. After starring a bit more at the code I saw that

• you manipulated the pointer text_ptr++
• incremented i only in the else part of the loop
• printed text_ptr++ and text_ptr+i

... what is hard to understand So I completely revised my version:

int i  = 0;
int up = 1; /* up = 1 means next char should be upper case*/
char* text_ptr = text;

while (*(text_ptr+i) != '\0') { /* could have been: while(text[i]) */
    if(!up)
      if(*(text_ptr+i-1)==' ' && toupper(*(text_ptr+i))=='I' &&  
        (*(text_ptr+i+1)==' ' || *(text_ptr+i+1)=='.' ||  // fix bracket here
         *(text_ptr+i+1)=='!' || *(text_ptr+i+1)=='?')) { // "i" foll. by one of those       
           up = 1;    /* capitalize i if all alone */
      }

    if(up)
      if (*(text_ptr+i)!=' ' && *(text_ptr+i)!='.' && // fix here
          *(text_ptr+i)!='!' && *(text_ptr+i)!='?') { // anything else than these
            putchar(toupper(*(text_ptr+i))); // toupper and reset up
            up = 0;
        } /* end if */
        else
            putchar(tolower(*(text_ptr+i))); // just print
    else
    {
        putchar(tolower(*(text_ptr+i)));
        if (*(text_ptr+i)=='?' || *(text_ptr+i)=='.' || *(text_ptr+i)=='!')
            up = 1;
    } /* end else */
    i++;
}/* end while */

Note that this version does require the toupper again. Otherwise correct I will be lowered. Your fourth if works fine as well (I oversaw, that you don't reset the up flag for spaces).