In 3-mandatory-implement/3-to-pounds.js, created a reusable function toPounds with input condition checks

Author: TzeMingHo

Sprint-2/3-mandatory-implement/3-to-pounds.js

@@ -4,3 +4,64 @@
 // You will need to declare a function called toPounds with an appropriately named parameter.
 
 // You should call this function a number of times to check it works for different inputs
+
+/* Code from Sprint-1 below for reference
+const penceString = "399p";
+
+const penceStringWithoutTrailingP = penceString.substring(
+  0,
+  penceString.length - 1
+);
+
+const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+const pounds = paddedPenceNumberString.substring(
+  0,
+  paddedPenceNumberString.length - 2
+);
+
+const pence = paddedPenceNumberString
+  .substring(paddedPenceNumberString.length - 2)
+  .padEnd(2, "0");
+
+console.log(`£${pounds}.${pence}`);
+*/
+
+function toPounds(penceString) {
+  if (typeof penceString !== "string" || !penceString.endsWith("p")) {
+    console.log("Invalid input, please provide a penceString ending with 'p'");
+    return "Invalid input, please provide a penceString ending with 'p'";
+  }
+
+  const penceStringWithoutTrailingP = penceString.substring(
+    0,
+    penceString.length - 1
+  );
+
+  if (Number.isNaN(Number(penceStringWithoutTrailingP))) {
+    console.log("Invalid input, please provide a numeric penceString");
+    return "Invalid input, please provide a numeric penceString";
+  }
+
+  const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0");
+  const pounds = paddedPenceNumberString.substring(
+    0,
+    paddedPenceNumberString.length - 2
+  );
+
+  const pence = paddedPenceNumberString
+    .substring(paddedPenceNumberString.length - 2)
+    .padEnd(2, "0");
+
+  console.log(`£${pounds}.${pence}`);
+  return `£${pounds}.${pence}`;
+}
+
+toPounds("399p");
+toPounds("5p");
+toPounds("89p");
+toPounds("1234p");
+toPounds("0p");
+toPounds("70000p");
+toPounds("abcp");
+toPounds(500);
+toPounds("abc");