My initialized variable is displayed empty - c++

Question

My string d is displayed empty (not even a space) on my console, this is getting me confused since I initialized it to "NULL" and I am trying to assign a new value to it which isn't a empty value.
int main(){
string user_String[99];
int user_Input = 0;
cout << "Please insert up to one hundred Strings: ";
cin >> user_Input;
//Check for range
bool check = false;
while( check == false){
if (user_Input < 1 || user_Input >100){
cout << "Please insert up to one hundred Strings: ";
cin >> user_Input;}
else{
check = true;
break;}
}
//User input
cout <<"Please enter string"<< endl;
for (int counter = 0; counter < user_Input; counter++){
int counter2 = counter + 1;
cout << "Enter String " << counter2 << ": ";
cin >> user_String[counter];
}
//Loopig for most letters
string c = "NULL";
for(int counter = 0; counter < user_Input; counter++){
//Making Sure Coun doesn't go out of range
int coun = 0;
if (counter < user_Input){
coun = counter +1;}
else{
coun = counter;
}
string a = user_String[counter];
string b = user_String[coun];
if (a.length() < b.length() && c == "NULL"){
c = b;
}
if(a.length() < b.length() && c!="NULL" && c.length() < b.length()){
c = b;
}
else{
continue;
}
}
cout << "The string "<< c <<" have the most letters." << endl;
//Looping for least letters
string d = "NULL";
for(int counter = 0; counter < user_Input; counter++){
//Making Sure Coun doesn't go out of range
int coun = 0;
if (counter < user_Input){
coun = counter +1;}
else{
coun = counter;
}
string a = user_String[counter];
string b = user_String[coun];
if (a.length() > b.length() && d == "NULL"){
d = b;
}
if(a.length() > b.length() && d!="NULL" && d.length() > b.length()){
d = b;
}
else{
continue;
}
}
cout << "The string " << d <<" have the least letters." << endl;
system("pause");
return 0;
}

Answer 1

You allow the user to enter up to 100 strings, but your array can only hold up to 99 strings. If they actually enter 100 strings, the last string will corrupt memory, assume your code does not crash altogether.
Also, your letters loops have some faulty logic in them. if (counter < user_Input) will always be true, so coun will always be counter+1 and thus exceed the bounds of the array when counter reaches the end of the array. Also, your loops are unnecessarily complex for what they are trying to do.
Try this instead:
int main()
{
string user_String[100];
int user_Input;
do
{
cout << "Please enter the number of Strings (1-100): ";
if (cin >> user_Input)
{
if ((user_Input >= 1) && (user_Input <= 100))
break;
}
else
cin.clear();
}
while (true);
for (int counter = 0; counter < user_Input; ++counter)
{
cout << "Enter String " << counter + 1 << ": ";
cin >> user_String[counter];
}
string b = user_String[0];
for(int counter = 1; counter < user_Input; ++counter)
{
string a = user_String[counter];
if (a.length() > b.length())
b = a;
}
cout << "The string " << b << " has the most letters." << endl;
b = user_String[0];
for(int counter = 1; counter < user_Input; ++counter)
{
string a = user_String[counter];
if (a.length() < b.length())
b = a;
}
cout << "The string " << b <<" has the least letters." << endl;
system("pause");
return 0;
}
With that said, you can get rid of the array altogether and merge the loops together:
int main()
{
string user_String;
int user_Input;
do
{
cout << "Please enter the number of Strings: ";
if (cin >> user_Input)
{
if (user_Input >= 1)
break;
}
else
cin.clear();
}
while (true);
string fewestLetters, mostLetters;
for (int counter = 1; counter <= user_Input; ++counter)
{
cout << "Enter String " << counter << ": ";
cin >> user_String;
if (counter == 1)
{
mostLetters = user_String;
fewestLetters = user_String;
}
else
{
if (user_String.length() > mostLetters.length())
mostLetters = user_String;
if (user_String.length() < fewestLetters.length())
fewestLetters = user_String;
}
}
cout << "The string " << mostLetters << " has the most letters." << endl;
cout << "The string " << fewestLetters << " has the least letters." << endl;
system("pause");
return 0;
}