Eric Matthew

What small thing did you over look or perhaps didn't click-in/notice right away for you that caused so much frustration?

Awhile back ago, I had a difficult time parsing/splitting a CSV(Comma Seperated Values) file that had fields with commas in them "Plumbing & Cleaning, Inc." and "$1,999.00". So I read up on Regular Expressions hoping to get some voodoo magic working for a few days.
Then I realized I could just excel to select all the Strings and Integers, find & replace all the "," with "". Bam, all extra commas gone. Don't know how this slipped my mind.

How about yourself? What can we learn from your pain and suffering?

Thanks for the response Henry, I thought about going through that route - just storing them as Integers/ints than when the values (for the Integers) are called, then checking to see if the value is greater than or less the known boundaries for zip codes. Seems a lot better than storing a bunch numerical types as Strings.

I'm making a program that is storing over 40,000 different zip codes and many of these zip codes have leading zeroes. I know I can use String to get around that but I learned that it's best to avoid using Strings for numerical types of data so I'm trying to avoid that route. Or is it best for this particular case to use Strings as opposed to the numerical types? Plus, I just read "Strings are bad" https://coderanch.com/how-to/java/StringsAreBad so that's why I'm mainly avoiding wanting to use Strings as well.

Oh, just to clarify. I understand that 00555 is the same as 555 and such.

Additional info if it helps: The zip codes are stored in txt file that are read from a scanner object.

Here's the code FWIW

package veterans.opt; import java.io.File; import java.io.FileNotFoundException; import java.util.ArrayList; import java.util.HashMap; import java.util.Scanner; public class ZipCodesTest { public static void main(String[] args) { HashMap<String, String> zipCodeMap = new HashMap<>(); ArrayList<String> zipCodeList = new ArrayList<>(); ArrayList<String> areaList = new ArrayList<>(); try { Scanner sc = new Scanner(new File("zipcodes.txt")); while (sc.hasNextLine()){ String[] tokenizer = sc.nextLine().split(" "); //Each line consist solely of the zip code followed by a space and the area it is in. Ex: "76544 TX" String zipCode = tokenizer[0]; String area = tokenizer[1]; zipCodeMap.put(zipCode, area); zipCodeList.add(zipCode); areaList.add(area); } sc.close(); } catch (FileNotFoundException e) { System.out.println("Error: File not found."); e.printStackTrace(); } for (int i = 0; i < zipCodeList.size(); i++){ System.out.printf("For the zip code %s, the area it is located is in %s%n", zipCodeList.get(i), zipCodeMap.get(zipCodeList.get(i))); } } }

And oh, I know I can make my code a bit more clearer by removing unneeded variables but I left everything in place til I can get some guidance how to proceed.

This isn't homework or anything school related, just a small part of a personal project of mine. My main personal project searches given URLs and other text files looking for specific key words, keeps a count on how many times it was found and stores the values in a map object. This, soon to be a method, took longer than I expected or maybe I'm just really tired. Open to any improvements or criticism.

My intentions with this code is just to simply return a String, a sentence in which the specific key word was found, and print it out or perhaps store it in a List and print it later..
package ericsStringstuff; import javax.swing.JOptionPane; public class StringTest { public static void main(String[] args) { String text = " The dog jumped over the rabbit. The cat, as the mouse watched, then chased the dog and fought him. " + "The dog and cat finally stopped fighting and started dancing."; String keyWord = JOptionPane.showInputDialog("Please enter a key word"); int keyWordIndex = text.indexOf(keyWord); int endingIndex = text.indexOf(".", keyWordIndex); int beginningIndex = 0; char[] temp = text.substring(0, endingIndex).toCharArray(); for (int i = temp.length-1; i > 0; i--){ if (temp[i] == '.') { beginningIndex = i; break; } } String line = text.substring(beginningIndex+1, endingIndex +1); System.out.println(line); } }

bump. still looking.

If there is, I can't find it. Any help appreciated. Thanks.

Nice analogy Tim

I have a method that test whether an array's elements are all equal. The method contains a for loop to test, and if they are equal, increments a counter. But for some reason, my counter is increasing more than the times I am even testing it.

for (int y = 0; y < rank.length; y++) { if (rank[0].getsuit() != rank[y].getsuit()) { break ; } else { countFlush++; //System.out.println("You have a flush!" + dealtHand.toString()); } }

This is part of the method. There is more to it but I feel as though I'm forgetting something more trivial.

Basically I just want the keys to increment different int counter variables each time the keys are retrieved.

Example:

import java.lang.reflect.Method; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.TreeSet; public class PokerDeck { int countFlush = 0; int countFh = 0; int countFoak = 0; HashMap<HandType, Method> results = new HashMap<>(); results.put(HandType.FLUSH, tabCounter(1)); results.put(HandType.FULL_HOUSE, tabCounter(2)); results.put(HandType.FOUR_OF_A_KIND, tabCounter(3)); void tabCounter(int numb) { if (numb == 1) { countFlush++; } else if (numb == 2) { countFh++; } else countFoak++; } public enum HandType { FLUSH, FULL_HOUSE, FOUR_OF_A_KIND; } }

Not sure if I'm on the right track. A bit lost here. Thanks CodeRanch!

Bear Bibeault wrote:

Eric Matthew wrote:I understand you may want to make a variable of an interface type

Then you understand why the variable should be List and not ArrayList.

So I'm not sure what it is that you do not understand.

I think my confusion arises from tutorials and code examples that do it this way when the ArrayList they're making is only going to be used only for one purpose. If there's no intention to change it later, why not just make List<> to ArrayList<>. But I think I fully grok it. Thank you.

Example

public MyClass1 { List<Student> myArr = new ArrayList<>(); }

why is List added before <Student> since ArrayList already implements the List interface by default. Just seems redundant. Why not make it like this:

public MyClass { ArrayList<Student> myArr = new ArrayList<>(); }

I understand you may want to make a variable of an interface type but I don't understand why classes that already implement an interface in the Java API do this. Maybe I'm thinking of this the wrong way. Any clarification of this would be appreciated. Thank you coderanch.

edit: Is it because if I decide later I want to change value of the variable( to linkedlist or vector) I wouldn't be able since it was declared it of type ArrayList<> instead of List<> ?

Thank you Piet and Ritchie for your replies and possible solutions. Despite how daunting it looks, I really enjoyed looking over them and look forward to learning more.

And thank you Robert for your comment, I don't know why I didn't see it that way before but now looking it that way makes it much more clearer in my head now.

I believe I found a solution that doesn't involve ArrayList, Collections, Streams or anything scary that I haven't learned yet. Just for and if loops.

Here is the code without any comments.
package tuesdayjulydeletelater; import java.util.Random; public class LottoSim { public static void main(String[] args) { Random ranObj = new Random(); int[] lottoBalls = new int[10]; lottoBalls[0] = 1 + ranObj.nextInt(9); for (int i = 1; i < lottoBalls.length; ++i) { lottoBalls[i] = 1 + ranObj.nextInt(9); for (int j = 0; j < i; j++) { if (lottoBalls[j] == lottoBalls[i]) { lottoBalls[i] = 1 + ranObj.nextInt(9); j = 0; } } System.out.println("Lotto Ball #" + i + " has been picked and is " + lottoBalls[i]); } } }


The code again but with comments.
package tuesdayjulydeletelater; import java.util.Random; public class LottoSim { public static void main(String[] args) { Random ranObj = new Random(); int[] lottoBalls = new int[10]; lottoBalls[0] = 1 + ranObj.nextInt(9); //Loop that fills the lottoBalls array for (int i = 1; i < lottoBalls.length; ++i) { lottoBalls[i] = 1 + ranObj.nextInt(9); //nested for loop that starts at the initial value of the array, this for loops repeats for as many array elements have been initialized. for (int j = 0; j < i; j++) { // Nested if statement to see if the initial value of lottoBall array is equal to the current element of the array. if (lottoBalls[j] == lottoBalls[i]) { //If the above statement is true, then the current array element's value is changed "randomly". lottoBalls[i] = 1 + ranObj.nextInt(9); // J is set to zero to test again (pseudo recursive). j = 0; } } //If the nested if statement is false, no array element is changed, String below is printed and we jump back to the first for loop // and go again till the loop condition is false. System.out.println("Lotto Ball #" + i + " has been picked and is " + lottoBalls[i]); } } }

Feel free to not hold back and critique any inefficiencies you notice or any adjustments that can be made.

Is there any way to do this without resorting to using ArrayList and Collections.shuffle? I'm just trying to figure out if it is possible using a series of loops and or booleans.

package prayitworks;

public class Bored { static int[] lottoBalls = new int[11]; static int[] tempArray = new int[11]; static int counter = 0; public static int ranNum() { int drawedNum = 1 + (int)(Math.random()* 6); return drawedNum; } }

Main method below

package prayitworks; public class BoredHome { public static void main(String[] args) { for (int i = 0; i < Bored.lottoBalls.length; i++) { Bored.lottoBalls[i] = Bored.ranNum(); System.out.println("Ball # " + i + " has been drawn and is " + Bored.lottoBalls[i]); //creates a copy of lottoBalls to store the values and test later for (int j = 0; j < i; j++) { Bored.tempArray[j] = Bored.lottoBalls[i]; } //below can be ignored, was just trying to brainstorm of something. for (int k = 0; k < Bored.lottoBalls.length; k++) { int m = 0; while (Bored.lottoBalls[k] == Bored.tempArray[m]) { Bored.lottoBalls[k] = Bored.ranNum(); } m++; } } } }

Any help would be appreciated.Thank for taking the time to look over.

Thanks for the replies guys, really do appreciate it. I haven't exactly figured out the problem but I believe it stems from a not knowing a more intermediate topic regarding java, "ArrayList", that I'm not familiar with. ArrayList objects are dynamic which is what I was looking for as opposed to a static number of elements.