From 3d7f4d6817987f22550a54fde9f0a829ec5bf432 Mon Sep 17 00:00:00 2001
From: Rob Hallam <0504004h@student.gla.ac.uk>
Date: Tue, 19 Sep 2023 22:31:38 +0100
Subject: [PATCH] (feat) Lab 6 Exercise 8 - left padding a string

---
 week1.java | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/week1.java b/week1.java
index 39adbd5..d99d9eb 100644
--- a/week1.java
+++ b/week1.java
@@ -255,6 +255,7 @@ class Lab6 extends Lab {
         new six5();
         new six6();
         new six7();
+        new six8();
     }
 
     /**
@@ -333,6 +334,56 @@ class Lab6 extends Lab {
         }
     }
 
+    /**
+     * Exercise 8 - String pad with specified character
+     */
+    class six8 extends Exercise {
+        public six8() {
+            super(8);
+            describeStringPadding("NoNeed", 4, '!');
+            describeStringPadding("Simon", 10, '@');
+            describeStringPadding("Zaphod Beeblebrox", 42, '?');
+            // describeStringPadding("Unicode", 10, '🤯'); aww
+        }
+
+        /**
+         * Print for display what we're padding and the result
+         *
+         * @param toPad   The string to pad eg "Simon"
+         * @param length  Desired length
+         * @param padChar Character to pad with
+         */
+        public void describeStringPadding(String toPad, int paddedLength, char padChar) {
+            System.out.println(String.format("Padding '%s' to length %d using padding character: %s",
+                    toPad, paddedLength, padChar));
+            System.out.println(stringLPad(toPad, paddedLength, padChar));
+        }
+
+        /**
+         * (Left-)pad a string with the specific character
+         *
+         * @param toPad   The string to pad eg "Simon"
+         * @param length  Desired length
+         * @param padChar Character to pad with
+         * @return The padded result
+         */
+        public String stringLPad(String toPad, int paddedLength, char padChar) {
+            // early out - return unmodified
+            if (toPad.length() >= paddedLength) {
+                return toPad;
+            }
+            // note that we could do this with String.repeat(), but since this is in the 'Loops'
+            // part of the lab, we should probably do this with a loop
+            // String paddedString = String.valueOf(padChar) + toPad;
+            String paddedString = toPad;
+            while (paddedString.length() < paddedLength) {
+                paddedString = String.valueOf(padChar) + paddedString;
+            }
+            return paddedString;
+        }
+
+    }
+
     /* TOASK - is there a better way of returning multiple values in Java?
        à la python, ie: return (quotient, remainder)
     */
@@ -391,6 +442,8 @@ class Lab6 extends Lab {
         /* Observations:
            - for even-sized triangles, preceding number of spaces starts at n=rows and decrements
            - for even-sized triangles even numbers have odd spaces and vice versa
+
+        TODO: handle multi-digit numbers
         */
         System.out.println(String.format(""));
         int spaces = num;