Tracing Dynamic Memory

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The last tracing is for dynamic memory. No matter how experienced in programming a person maybe they will always, always, ALWAYS trace dynamic memory. It is the most complex as both values and spots for them are kept track.

Depending on what language or level of Computer Science used this can wait till latter. Also read up on the language's specifics for dynamic memory, i.e. references and pointers to be sure.

Pointers

When a pointer is declared draw a little dot for it and place its name beside.
If a pointner is assigned a value to point to draw an arrow to it. If a new spot is given erase/cross out the old arrow and draw a new one.
If a new operator is used draw a box as if a normal variable was be created but do not give is a name.
Do not remove a variable space, i.e. a box unless a delete is used.
Use a standard symbol by itself, no box or point, to represent NULL. Typical ones are N or 0.
If a reference is declared write the name of it by the box of the variable it is referencing to.
Keep track of whether the value of the pointer/reference is being changed, or the value of the variable which the pointer/reference is refering to changes.
Take your time and space needed to check throughly.

int x = 2; int p = new int(4); p = &x; *p = 3; p = null;		Declare integer x with value 2. Declare pointer p with initial new integer with a value of 4. P is assigned to the address of x, i.e. p points to x. Object of p is assigned 3. P is set to NULL. At the end, x is 3, there is a loose integer with a value of 4, and p is NULL. With this tracing notice how the memory leak of that 4 by itself.
int p, q = new int(0); p = q; q = 3; p = 2; delete p; q = new int(4); delete q; p = q = NULL;		Declare two pointers to integers p and q. Q pointes to a new interger with a value of 0; P points to the same thing as q. Object which q points to is 3. Object which p points (which is the same integer q points to) is 2. Delete the integer p points to, so p and q point to nothing. Q points to a new integer (new box) with a value of 4. Integer which q points to is deleted. P and q are set to point to NULL.

References

If a reference is declared write the name of it by the box of the variable it is referencing to.
Keep track of whether the value of the pointer/reference is being changed, or the value of the variable which the pointer/reference is referring to changes.
Take your time and space needed to check throughly.
No that is not a typo, taking your time and keeping track of pointer or thing that the pointer points to is critical.

int x = 4;  int &r = x; int *p;
p = &x;
r = 2;
*p = 5;
p = new int(2);
int &s = *p;
p = NULL;
s = 1;

Declare an integer x, reference to an interger r which referes to x, and a pointer to an integer p.
P points to the address of x.
R is assign 2, (and so is x).
Object which p points to (x) is 5.
P points to a new integer with a value of 2.
A reference to an integer s is declared, and refered to the object which p points to.
P points to NULL.
S is assigned 1.

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