Fix getLastDigit function to use its parameter and update predictions and explanations

Author: MohammedNaru

Sprint-2/2-mandatory-debug/2.js

@@ -3,6 +3,10 @@
 // Predict the output of the following code:
 // =============> Write your prediction here
 
+// I predict that the code will output 'undefined' for each call to getLastDigit because the function does not use its parameter.
+
+// This program should tell the user the last digit of each number.
+
 const num = 103;
 
 function getLastDigit() {
@@ -15,10 +19,27 @@ console.log(`The last digit of 806 is ${getLastDigit(806)}`);
 
 // Now run the code and compare the output to your prediction
 // =============> write the output here
+
+// The output will be:
+// The last digit of 42 is undefined
+// The last digit of 105 is undefined
+// The last digit of 806 is undefined
+
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The output is 'undefined' because the function getLastDigit does not use its parameter.
+// It always returns the last digit of the variable num, which is 103, not the number passed to it.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
 
-// This program should tell the user the last digit of each number.
+function getLastDigit(num) {
+  return num.toString().slice(-1);
+}
+
+console.log(`The last digit of 42 is ${getLastDigit(42)}`);
+console.log(`The last digit of 105 is ${getLastDigit(105)}`);
+console.log(`The last digit of 806 is ${getLastDigit(806)}`);
+
+// This program should tell the user the last digit of each number. 
 // Explain why getLastDigit is not working properly - correct the problem