Programming in C

232 Chapter 10 Character Strings
to be inserted, and the position in the source string where the string is to be
inserted. So, the call
insertString (text, "per", 10);
with text as originally defined in the previous exercise, results in the character
string "per" being inserted inside text, beginning at text[10].Therefore, the
character string "the wrong person" is stored inside the text array after the
function returned.
8. Using the findString, removeString,and insertString functions from preceding
exercises, write a function called replaceString that takes three character
string arguments as follows
replaceString (source, s1, s2);
and that replaces s1 inside source with the character string s2.The function
should call the findString function to locate s1 inside source, then call the
removeString function to remove s1 from source, and finally call the
insertString function to insert s2 into source at the proper location.
So, the function call
replaceString (text, "1", "one");
replaces the first occurrence of the character string "1" inside the character string
text, if it exists, with the string "one". Similarly, the function call
replaceString (text, "*", "");
has the effect of removing the first asterisk inside the text array because the
replacement string is the null string.
9. You can extend even further the usefulness of the replaceString function from
the preceding exercise if you have it return a value that indicates whether the
replacement succeeded, which means that the string to be replaced was found
inside the source string. So, if the function returns true if the replacement succeeds
and false if it does not, the loop
do
stillFound = replaceString (text, " ", "");
while ( stillFound = true );
could be used to remove all blank spaces from text, for example.
Incorporate this change into the replaceStrings function and try it with various
character strings to ensure that it works properly.
10. Write a function called dictionarySort that sorts a dictionary, as defined in
Programs 10.9 and 10.10, into alphabetical order.
11. Extend the strToInt function from Program 10.11 so that if the first character of
the string is a minus sign, the value that follows is taken as a negative number.