Add comments for CSVUtility.java

Week9/Assignment9/src/CSVUtility.java

@@ -19,15 +19,15 @@ public class CSVUtility {
 		// ENTER CODE HERE
 		Scanner sc = new Scanner(new File(filename)); // Create a Scanner to take in the file at path filename
 		int length = 0; //Create a length variable and initialize it to zero
-		for (length = 0; sc.hasNext(); length++) 
-			sc.nextLine();
+		for (length = 0; sc.hasNext(); length++) //Find Line amount | Loop until there's no next line,each loop length++
+			sc.nextLine();// Go to the next line
 		sc.close(); //Close the Scanner to prevent resource leak
-		String[] filedata = new String[length];
+		String[] fileData = new String[length]; //create a 1D array to store file data
 		sc = new Scanner(new File(filename)); //Reinitialize the closed scanner
 		for (int i = 0; i < length; i++)
-			filedata[i] = sc.nextLine();
+			fileData[i] = sc.nextLine(); //Send line i to array fileData at index i-1 
 		sc.close(); //Close the Scanner to prevent resource leak
-		return filedata; //Return
+		return fileData; //Return array filled with file data
 	}
 
 	/**
@@ -41,15 +41,12 @@ public class CSVUtility {
 	 */
 	public static String[][] readCSV(String filename, boolean header) throws FileNotFoundException {
 		// ENTER CODE HERE
-		String[] data = readFile(filename);
-		int lineOffset = header ? 1 : 0;
-		int maxElement = 0;
-		for (int i = lineOffset; i < data.length; i++)
-			maxElement = Math.max(data[i].split(",").length, maxElement);
-		String[][] csv = new String[data.length - lineOffset][maxElement];
-		for (int i = lineOffset; i < data.length; i++)
-			csv[i - lineOffset] = data[i].split(",");
-		return csv;
+		String[] data = readFile(filename); //Read the file
+		int lineOffset = header ? 1 : 0; //do we have header? if yes, start at line 2
+		String[][] csv = new String[data.length - lineOffset][];
+		for (int i = lineOffset; i < data.length; i++) //Go through all rows
+			csv[i - lineOffset] = data[i].split(","); //Array.split(String delimiter) return a 1D array with each element seperated by the delimiter
+		return csv; //Send back the CSV file
 
 	}
 

Week9/Assignment9/src/CSVUtilityTest.java

@@ -26,6 +26,10 @@ public class CSVUtilityTest {
 		ArrayUtility.show(CSVUtilityGiven.readCSV("course-db.csv", true));
 		System.out.println("Your result:");
 		ArrayUtility.show(CSVUtility.readCSV("course-db.csv", true));
+		System.out.println("----------------------------------------");
+		ArrayUtility.show(CSVUtilityGiven.readCSV("uneven.csv", false));
+		System.out.println("Your result:");
+		ArrayUtility.show(CSVUtility.readCSV("uneven.csv", false));
 	}
 	
 }

Week9/Assignment9/uneven.csv

@@ -0,0 +1,10 @@
+uneven
+Player01,4,4,6,3,4,6,3,5,4,6,4,4,3,6
+Player02,4,4,4,5
+Player03,4,5,5,4,6,5,5,5,7,6,3,6,4,6,5,5,4,5
+Player04,5,6,4,3,5,4,7,4,6
+Player05,4,3,4,4,4,5,4,4,5,5,4,5,5,5,5,4,5,4
+Player06,3,4,4,3,3,4,4,4,5,5,3,4
+Player08,4,6,5,3,4,6,4,3,4,4,2,5,4,4,3,4
+Player09,5,5,8,4,5,4,5,3,6,6,5,4,5
+Player10,5,4,5,3,6,4,5,4,6,5,5