Strange letter print out from array c programming - c

Question

I am trying to delete the blank space between a string and print out the first word with isalpha() function.
When I print out, only the first letter prints out. exempel "hello big panda" I get "hhhhh" but I want the hole word "hello" instead
int main()
{
char inputString[]={"hello big panda"};
int k=0;
int i=0;
do
{
inputString[i];
i++;
}
while (inputString[i]=isalpha(inputString[i]));
for(i=0; inputString[i] !='\0' ;i++)
{
for (k=i; inputString[k] != '\0'; k++)
{
inputString[k] =inputString[i];
}
}
printf("%s", inputString);
return 0;
}
done this:
int printfirstword(char sentence[])
{
int k=0;
int i=0;
while (isalpha(sentence[i])) //checking for the first blank space
{
i++;
}
sentence[i] = '\0';
printf("%s\n", sentence);
return 0;
}
int main()
{
char sentence[100];
int wordNumber;
char answer;
printfirstword("Hello there")
return0;
}
But I don't want to change the string that is passed to it

Answer 1

What you can simply do is use a while loop instead of your do-while. You can simply increment i until you find the index of first blank space. Then using the value of i you can insert '\0' in your string. Output it and you are done. :)
#include <stdio.h>
#include<ctype.h>
int main()
{
char inputString[]={"hello big panda"};
int k=0;
int i=0;
while (isalpha(inputString[i])) //checking for the first blank space
{
i++;
}
inputString[i] = '\0';
printf("%s", inputString);
return 0;
}
If you would like to keep the original string then you could simply make a new string say newStr and then
while (isalpha(inputString[i])) //checking for the first blank space
{ newStr[i]=inputString[i]; //copy first word into newStr
i++;
}
newStr[i] = '\0';
printf("%s", newStr);

Answer 2

Your function must do 3 things as it works through the sentence finding words. (1) always check for the end of the string to prevent an attempted read beyond the end of the sentence; and (2) locate and print the requested word at the index given; and (3) handle the condition where the user requests a word index greater than that available.
(you should always test the sentence you are passed in the function to make sure the pointer isn't a NULL pointer, and that the contents of the sentence is simply the '\0' character indicating an empty-string)
An easy way to do this (after you have tested the input string), is to set up a continual loop, that repeatedly read the characters of a word, checks if it is the word to print (if so it prints), and if not read and discard all the non-alpha characters before the next word, and then repeats.
Something simple like the following works. It takes the sentence (or updated position within the sentence) and the index for the word to print zero-indexed, e.g. (0, 1, 2, ...) and then loops a described above.
(note: you can change the zero-index scheme to a 1, 2, 3, ... word-number scheme by initializing n=1; instead of 0 -- but since everything in C is zero indexed, that is left to you)
#include <stdio.h>
#include <ctype.h>
int prnword (const char *s, int nwrd)
{
int n = 0; /* word counter */
char *p = s; /* pointer to s */
if (!s || !*s) { /* test s not NULL and not empty */
fprintf (stderr, "error: string NULL, empty or at end.\n");
return 0;
}
for (;;) { /* loop continually until exit condition reached */
while (*p && isalpha(*p)) { /* loop over chars in s */
if (n == nwrd) /* if requested index */
putchar (*p); /* print all chars */
p++; /* increment pointer */
}
while (*p && !isalpha(*p)) /* iterate find next alpha */
p++;
if (++n > nwrd) /* if past our word, break */
break;
if (!*p) /* if end reached, break */
break;
}
if (n <= nwrd) { /* check request exceeds avaialble words */
fprintf (stderr, "error: request word '%d' "
"exceeds available wprds indexes.\n", nwrd);
return 0;
}
putchar ('\n'); /* tidy up with new line */
return p - s; /* return number of chars to next alpha */
}
int main (void) {
char str[] = "hello big panda";
int nchars = 0;
/* example -- all words in order
* passing update string position
*/
nchars = prnword (str, 0);
nchars += prnword (str + nchars, 0);
nchars += prnword (str + nchars, 0);
putchar ('\n');
/* request exceed available zero-based word indexes */
nchars = 0;
nchars += prnword (str, 3);
putchar ('\n');
/* print 2nd word only */
nchars = 0;
nchars = prnword (str, 1);
putchar ('\n');
return 0;
}
Example Use/Output
Note the first block of calls to prnword print each of the words in the sentence, saving the number of characters returned by prior calls and using that to start the function reading the 1st character of the desired word, meaning you are always looking for word index 0.
The second call intentionally gives an index one past the last word to force handling the error.
And finally, the last call simply says "Go print word 2" (index 1) starting from scratch.
Example Use/Output
$ ./bin/words
hello
big
panda
error: request word '3' exceeds available wprds indexes.
big
Look things over and let me know if you have questions.