All character functions in C++

All character functions in C++ 

#include<iostream>
#include<conio.h>
  using namespace std;
   int isUpper(char ch)
     {
     if(ch>=65&&ch<=90)
      return 1;
     else
      return 0;
  }
   int isLower(char ch)
     {
     if(ch>=97&&ch<=122)
      return 1;
     else
      return 0;
  }

 int isDigit(char ch)
     {
     if(ch>=48&&ch<=57)
      return 1;
     else
      return 0;
  }
 
    int isAlph(char ch)
     {
     if(ch>=97&&ch<=122||ch>=65&&ch<=90)
      return 1;
     else
      return 0;
  }
 
 int isAlnum(char ch)
     {
     if(ch>=97&&ch<=122||ch>=65&&ch<=90||ch>=48&&ch<=57)
      return 1;
     else
      return 0;
  }
 int isBlank(char ch)
     {
     if(ch==' '||ch=='\t')
      return 1;
     else
      return 0;
  }
 char toUpper(char ch)
     {
     ch=ch-32;
     return ch;
  }
 char toLower(char ch)
     {
     ch=ch+32;
     return ch;
  }
 
 int isSpace(char ch)
     {
     if(ch==' '||ch=='\t')
      return 1;
     else
      return 0;
  }
 int isCntrl(char ch)
     {
     if(ch=='\n'||ch=='\t'||ch=='\r'||ch=='\a')
      return 1;
     else
      return 0;
  }
  
 int main()
   {
    if(isLower('c'))
      cout<<"Charater is lower.";
    else
     cout<<"Charater is  Not lower.";
    
    if(isAlnum('8'))
       cout<<"\nAlphanumeric character.";
    else
       cout<<"\nNot alphanumeric character.";
    
     char ch='\a';
     if(isCntrl(ch))
      cout<<"\nControl character";
    else
     cout<<"\nNot Control character";
     
     if(isBlank(' '))
       cout<<"\nBlank space.";
    else
       cout<<"\nNot Blank space.";
    
   }

Output:-