C++ exam question on string class implementation
- by Carlucho
I just took an exam where i was asked the following:
Write the function body of each of the methods GenStrLen, InsertChar and StrReverse for the given code bellow. You must take into consideration the following;
How strings are constructed in C++
The string must not overflow
Insertion of character increases its length by 1
An empty string is indicated by StrLen = 0
class Strings {
private:
char str[80];
int StrLen;
public:
// Constructor
Strings() {
StrLen=0;
};
// A function for returning the length of the string 'str'
int GetStrLen(void) {
};
// A function to inser a character 'ch' at the end of the string 'str'
void InsertChar(char ch) {
};
// A function to reverse the content of the string 'str'
void StrReverse(void) {
};
};
The answer I gave was something like this (see bellow). My one of problem is that used many extra variables and that makes me believe am not doing it the best possible way, and the other thing is that is not working....
class Strings {
private:
char str[80];
int StrLen;
int index; // *** Had to add this ***
public:
Strings(){
StrLen=0;
}
int GetStrLen(void){
for (int i=0 ; str[i]!='\0' ; i++)
index++;
return index; // *** Here am getting a weird value, something like 1829584505306 ***
}
void InsertChar(char ch){
str[index] = ch; // *** Not sure if this is correct cuz I was not given int index ***
}
void StrRevrse(void){
GetStrLen();
char revStr[index+1];
for (int i=0 ; str[i]!='\0' ; i++){
for (int r=index ; r>0 ; r--)
revStr[r] = str[i];
}
}
};
I would appreciate if anyone could explain me toughly what is the best way to have answered the question and why. Also how come my professor closes each class function like " }; " i thought that was only used for ending classes and constructors only.
Thanks a lot for your help.
