Code can run but doesn't show the Result in Eclipse.? - c++

Question

Why the example code below can run fine on Visual Studio. In Eclipse, NetBean or CodeBlock the code can run but can't show the Result? Thanks All.
Ex: input one string.
a/ Uppercase first letter.
b/ Remove spaces inside the string.
#include "iostream"
#include "string.h"
using namespace std;
#define MAX 255
//uppercase first letter
char* Upper(char* input)
{
char* output = new char[MAX];
bool isSpace = false;
for (int i = 0; i < strlen(input); i++)
{
output[i] = input[i];
if (isSpace)
{
output[i] = toupper(output[i]);
isSpace = false;
}
if (output[i] == ' ') isSpace = true;
}
output[strlen(input)] = '\0'; // end of the string
output[0] = toupper(output[0]); // first character to upper
return output;
}
//remove space inside the string
char* RemoveSpaceInside(char* input)
{
char* output = new char[MAX];
strcpy(output, input);
int countWhiteSpace = 0;
for (int i = 0; i < strlen(output); i++)
{
if (output[i] == ' ')
{
for (int j = i; j < strlen(output) - 1; j++) // move before
{
output[j] = output[j + 1];
}
countWhiteSpace++;
}
}
output[strlen(output) - countWhiteSpace] = '\0'; // end of the string
return output;
}
int main()
{
char* name = new char[MAX];
cout << "Enter name: "; cin.getline(name, strlen(name));
cout << "Your name: " << name << endl;
cout << "\n******* Q.A *******\n";
char* qa = Format2VN(name);
cout << qa << endl;
cout << "\n******* Q.B *******\n";
char* qb = RemoveSpaceInside(name);
cout << qb << endl;
return 0;
}

Answer 1

char* name = new char[MAX];
cout << "Enter name: ";
cin.getline(name, strlen(name));
Calling strlen(name) will invoke undefined behavior, because you haven't initialized the array. Poor strlen will try to find the NUL character in an uninitialized byte mess. Definitely not a good idea.
What you probably want is:
cin.getline(name, MAX); // not sure if MAX or MAX-1 or whatever
In general, do yourself a favor and replace char* with std::string. Also, get a good C++ book.
Here is how your example would look like in actual C++:
#include <algorithm>
#include <cctype>
#include <iostream>
#include <string>
std::string upper_first_letter(std::string s)
{
if (!s.empty()) s[0] = toupper(s[0]);
return s;
}
std::string remove_spaces(std::string s)
{
s.erase(std::remove_if(s.begin(), s.end(), isspace), s.end());
return s;
}
int main()
{
std::string name;
std::cout << "Enter name: ";
std::getline(std::cin, name);
std::cout << name << '\n';
std::cout << upper_first_letter(name) << '\n';
std::cout << remove_spaces(name) << '\n';
}