Thread: need help in string compare

uhh hey guys

i have some problem in string compare. here's a portion of my code.

here's the what i use to store the identifiers

Code:

string a[4];

   a[0]="if(i==1||i==x)";
   a[1]="else if(j==1||j==x)";
   a[2]="else if(j==i)";
   a[3]="while(x!=20)";

and here's the execution code

Code:

if(a!=NULL)				
//check if array is empty
{
       for(int j=0; j<4; j++)                   
//compare identifiers with tokens
                  {
                  if(a[j]== tokens[j])
	{cout<<a[j];}

                      else
						{cout<<tokens[j];}
                  }

see the problem is that when i compile the program the system is hanged for whatever reason that i don't know. i asked a few friends and they say that the problem is with those codes i posted above. can somebody please tell me what's wrong with the codes??