Part 3
Substring Length

As you have just learned, Part_btwn() extracts the substring located between two specified positions.

Prt_btwn(firstPsn, lastPsn, whichString);

Using the two positions we can calculate the length of the resulting substring:

|substring| = lastPsn - firstPsn;

Example:
α = <7, 2, 4, 1, 3 >;
β = Prt_btwn (1, 4, α) = <2, 4, 1 >;
| β | = 4 - 1 = 3;
The length of the substring β is 3.