Problem with char*

[Zivojin]

Does anybody knows that might trigger a breakpoint here

char * arr;
int t;
int length;

Stack(int a)//stack of characters
{
length=a;
arr=new char[length];//Here the program breaks 
//if (void* const block = malloc(size)) exception
t=-1;
}

[JLBorges]

Print out the value of length before you try new char[length] ;