c++ - uppercase letter input can't working in cpp programs -

i reading c++ right ,and got stuck in following program.

when provide string lower case letter, provides fine output, when go upper case letters, gets stuck after input.

here code:

`#include <iostream>`  #include <stdio.h>  #include "string.h"  using namespace std;  class base { public: int array(){     int i, n, p, z = 0;     char g[50];     string c[50];     char abc;      cout << "enter name :" << endl;     cin >> g;      = 0;     while (g[i] != 0)         if ((g[i] >= 'a' && g[i] <= 'z') || (g[i] <= 'a' && g[i] >= 'z')){             z++;             i++;         }     cout << "name of " << z << " elements" << endl;     {         (p = 0; p < z; p++)             cout << "a[" << p + 1 << "]=" << g[p] << endl;     }     cout << "enter element no.:";     cin >> n;     if(n >0 && n <= z){         cout << "a[" << n << "]=" << g[n-1] << endl;     }     (p = 0; p < z; p++){         char integer_string[50];         int integer = p+1;          sprintf(integer_string, "%d", integer);         char other_string[50] = "g[";         strcat(other_string, integer_string);         strcat(other_string, "]");         c[p]= other_string;     }     cout << "enter character :";     cin >> abc;      (p = 0; p < z; p++){         if(g[p] == abc){             cout <<abc<< "=a[" << p + 1 << "]"<< endl;             break;         }     }     return 0; } };  //-------------------------------------------------------------- int main(){      base b;     b.array();      return 0; } 

could tell me problem in program?

try changing

if ((g[i] >= 'a' && g[i] <= 'z') || (g[i] <= 'a' && g[i] >= 'z'))

to

if ((g[i] >= 'a' && g[i] <= 'z') || (g[i] >= 'a' && g[i] <= 'z'))

and deleting 3 ` , 2 in first line , 1 in last line.

---

update

adding #incude <cctype> head of code , using

if (islower(g[i]) || isupper(g[i]))

is better. avoid depending character code.

if (isalpha(g[i])) may work.