use parameter instead of hardcoded num variable

Author: remimarcelle

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

@@ -2,6 +2,9 @@
 
 // Predict the output of the following code:
 // =============> Write your prediction here
+// All 3 console.logs will print "3" because the getLastDigit
+// function ignores its parameter and always returns the hardcoded
+// const num which is 103. 
 
 const num = 103;
 
@@ -15,10 +18,30 @@ 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 is:
+// The last digit of 42 is 3
+// The last digit of 105 is 3
+// The last digit of 806 is 3
+
 // Explain why the output is the way it is
 // =============> write your explanation here
+// The function uses a hardcoded variable num = 103 from outside
+// the function instead of the num parameter that is passed to the 
+// function. Therefore, it always returns the last digit of 103.
+// To fix this I can remove the const num = 103 and add num as a 
+// parameter to the function  so each call to getLastDigit will use
+// the number passed in as an argument (its own input) instead of the
+// hardcoded value.
+
 // Finally, correct the code to fix the problem
 // =============> write your new code here
+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