Is it compulsory to initialize pointers in C++?

Question

Is it compulsory to initialize t in the following code, before assigning value to t? Is the code correct?

void swap(int *x, int *y)
{
    int *t;
    *t = *x;
    *x = *y;
    *y = *t;
}

Answer 1

You don't need pointer to begin with:

void swap(int *x,int *y)
{
    int t; //not a pointer!
    t=*x;
    *x=*y;
    *y=t;
}
int a = 10, b = 20;
swap( &a, &b); //<-----------note : Needed &

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Or maybe, you want the following swap function:

void swap(int & x,int & y) //parameters are references now!
{
    int t; //not a pointer!
    t=x;
    x=y;
    y=t;
}
int a = 10, b = 20;
swap(a,b); //<----------- Note: Not needed & anymore!

Answer 2

is the following section of code correct?

Nopes! Your code invokes Undefined behaviour because you are trying to dereference a wild pointer.

 int *t;
 *t=*x; // bad

Try this rather

 int t; // a pointer is not needed here
 t=*x; 

or this

int *t = x; // initialize the pointer

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