feat: add detailed breakdown of random number generation logic

Author: Tarawally

Sprint-1/1-key-exercises/4-random.js

@@ -3,7 +3,37 @@ const maximum = 100;
 
 const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 
-// In this exercise, you will need to work out what num represents?
-// Try breaking down the expression and using documentation to explain what it means
-// It will help to think about the order in which expressions are evaluated
-// Try logging the value of num and running the program several times to build an idea of what the program is doing
+// Breakdown of the 'num' declaration
+// The expression of `num` can be broken down into several discrete steps:
+
+// 1. `Math.random()`, this generates a random floating point number
+// This number is between 0 (inclusive) and 1 (exclusive)
+console.log("Math.random():", Math.random());
+
+// 2. `(maximum - minimum + 1)` this part simple resolve to 100
+console.log("maximum - minimum + 1:", maximum - minimum + 1);
+
+// 3. By multiplying steps 1 and 2, the floating point number is scaled from 0-1 to 0-100
+// This adjusted scale is defined by the `minimum` and `maximum` variables declared earlier
+console.log(
+  "Math.random() * (maximum - minimum + 1):",
+  Math.random() * (maximum - minimum + 1)
+);
+
+// 4. `Math.floor()` then rounds down to the nearest whole number
+// Turning the floating point number into a whole number and adjusting the range from 0-99
+console.log(
+  "Math.floor(Math.random() * (maximum - minimum + 1)):",
+  Math.floor(Math.random() * (maximum - minimum + 1))
+);
+
+// 5. Lastly, `+ minimum` shifts the result up by the value of 1
+// In effect, this adjusts the range from 0-99 to 1-100
+console.log(
+  "Math.floor(Math.random() * (maximum - minimum + 1)) + minimum:",
+  Math.floor(Math.random() * (maximum - minimum + 1)) + minimum
+);
+
+// The final result is a random whole number between minimum (1) and maximum (100)
+// Where 100 is an inclusive valid value in the range
+console.log("num:", num);