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Can this lengthy if-else Java code be improved by using arrays?

I'm trying to simplify this Java code by adding arrays, but I'm having difficulty.
The code that I have so far that works:
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Homework4A {
public static void main(String[] args) throws FileNotFoundException {
Scanner scan = new Scanner(System.in);
System.out.print("Enter name of the input file: ");
String fileName = scan.next();
try (Scanner inFile = new Scanner(new FileReader(fileName))) {
char number0 = '0';
char number1 = '1';
char number2 = '2';
char number3 = '3';
char number4 = '4';
char number5 = '5';
char number6 = '6';
char number7 = '7';
char number8 = '8';
char number9 = '9';
int count0 = 0;
int count1 = 0;
int count2 = 0;
int count3 = 0;
int count4 = 0;
int count5 = 0;
int count6 = 0;
int count7 = 0;
int count8 = 0;
int count9 = 0;
while (inFile.hasNextLine()) {
String line = inFile.nextLine();
for (int i = 0; i < line.length(); i++) {
if (line.charAt(i) == number0) {
count0++;
}
else if (line.charAt(i) == number1) {
count1++;
}
else if (line.charAt(i) == number2) {
count2++;
}
else if (line.charAt(i) == number3) {
count3++;
}
else if (line.charAt(i) == number4) {
count4++;
}
else if (line.charAt(i) == number5) {
count5++;
}
else if (line.charAt(i) == number6) {
count6++;
}
else if (line.charAt(i) == number7) {
count7++;
}
else if (line.charAt(i) == number8) {
count8++;
}
else if (line.charAt(i) == number9) {
count9++;
}
}
}
System.out.println("\n-= Count of Thistles in =-");
System.out.println("-= the Hundred Acre Wood =-\n");
System.out.println(" -----------");
System.out.println(" type count");
System.out.println(" -----------");
System.out.println(" 0 " + count0);
System.out.println(" 1 " + count1);
System.out.println(" 2 " + count2);
System.out.println(" 3 " + count3);
System.out.println(" 4 " + count4);
System.out.println(" 5 " + count5);
System.out.println(" 6 " + count6);
System.out.println(" 7 " + count7);
System.out.println(" 8 " + count8);
System.out.println(" 9 " + count9);
System.out.println(" -----------");
}
}
}
However, it's kind of a brute-force attack. The spot of difficulty I'm running into is figuring out where to create and pass arrays. Since the code has to read the external file, should the arrays be created and passed in the while statement?
For further reference, the text file that is being read looks like this:
Thistle Map
The goal is to count the occurrences of digits only.

As you stated, you could use arrays.
I would suggest 2 arrays
One to hold the digits to catch
Second one for the counts
Initialization of the arrays
char[] numbers = new char[10];
//initialize of numbers(char) to count
for(int i = 0; i < numbers.length; i++) {
numbers[i] = (char) ('0' + i);
}
int[] counts = new int[10]; //no initialization needed because int is default 0
In the for-loop where you iterate over the line, add a nested for loop, that iterates over the numbers-array. Here is the whole while loop:
while (inFile.hasNextLine()) {
String line = inFile.nextLine();
for (int i = 0; i < line.length(); i++) {
for(int j = 0; j < numbers.length; j++) {
if(line.charAt(i) == numbers[j]) {
counts[j]++;
}
}
}
}
For the output just use another for over the arrays:
for(int i = 0; i < numbers.length; i++) {
System.out.println(" "+ numbers[i] +" " + counts[i]);
}
Edit: Another solution using a Map
//...
Map<Character, Integer> charCounts = new HashMap<>();
for (int i = 0; i < 10; i++) {
charCounts.put((char) ('0' + i), 0);
}
while (inFile.hasNextLine()) {
String line = inFile.nextLine();
for (int i = 0; i < line.length(); i++) {
charCounts.computeIfPresent(line.charAt(i), (key, val) -> val + 1);
}
}
//...
for (Character number : charCounts.keySet()) {
System.out.println(" " + number + " " + charCounts.get(number));
}
With this solution you can easily extend your program to count any occuring character. Just remove the initialization of the map and add this line below the computeIfPresent.
charCounts.putIfAbsent(line.charAt(i), 1);

With Java 8 you can use Files.lines to get a Stream of all the lines in a file.
Then you can transform the stream to a stream over every char using flatMap and in the end collect it to a map that has the Character as key and the count of the character as value.
try (Stream<String> stream = Files.lines(Paths.get(fileName)) {
Map<Character, Long> charCountMap = stream
.flatMap(line -> line.chars().mapToObj(c -> (char) c))
.collect(Collectors.groupingBy(c -> c, Collectors.counting()));
System.out.println(" 0 " + charCountMap.getOrDefault('0', 0));
} catch (IOException e) {
e.printStackTrace();
}
Probably the way I would do it in a real world scenario, because it's short, but just for practice the other answers are better.

Yes. I would say it can be simplified a great deal with an array. You don't need seperate sentinels for the values, you can check they are in range and then use Character.digit to parse them. Something like,
Scanner scan = new Scanner(System.in);
System.out.print("Enter name of the input file: ");
String fileName = scan.next();
try (Scanner inFile = new Scanner(new FileReader(fileName))) {
int[] count = new int[10];
while (inFile.hasNextLine()) {
String line = inFile.nextLine();
for (int i = 0; i < line.length(); i++) {
if (line.charAt(i) >= '0' && line.charAt(i) <= '9') {
count[Character.digit(line.charAt(i), 10)]++;
}
}
}
System.out.println("\n-= Count of Thistles in =-");
System.out.println("-= the Hundred Acre Wood =-\n");
System.out.println(" -----------");
System.out.println(" type count");
System.out.println(" -----------");
for (int i = 0; i < count.length; i++) {
System.out.printf(" %d %d%n", i, count[i]);
}
System.out.println(" -----------");
}

You can use a single array for this and index notation. Each array index should hold the quantity of digits. Much more clear.
import java.io.FileReader;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Homework4A {
public static void main(String[] args) throws FileNotFoundException {
Scanner scan = new Scanner(System.in);
System.out.print("Enter name of the input file: ");
String fileName = scan.next();
try (Scanner inFile = new Scanner(new FileReader(fileName))) {
int[] count = new int[10];
while (inFile.hasNextLine()) {
String line = inFile.nextLine();
for (int i = 0; i < line.length(); i++) {
try {
int c = Character.getNumericValue(line.charAt(i));
count[c] += 1;
} catch (Exception e) { }
}
}
System.out.println("\n-= Count of Thistles in =-");
System.out.println("-= the Hundred Acre Wood =-\n");
System.out.println(" -----------");
System.out.println(" type count");
System.out.println(" -----------");
for (int i = 0; i < 10; i++)
System.out.println(" " + i + " " + count[i]);
System.out.println(" -----------");
}
}
}

Why is it that my character counter not increasing when the for loop goes?

I'm currently coding a program that takes in a string and a single character (if you decide to put a single one in that is) and (is supposed) to check how many times that character is in the string and at the end print out the amount of times it is in there. For some reason it isn't working and I would like some help; thank you!
import java.util.Scanner;
public class HowManyChars {
public HowManyChars() {
Scanner sc = new Scanner (System.in);
String askPhrase;
String askChar;
int charCounter = 0;
System.out.println("Enter a phrase");
askPhrase = sc.nextLine();
System.out.println("Enter a letter");
askChar = sc.nextLine();
for (int i = 0; i < askPhrase.length(); i++) {
if (askPhrase.substring(i, i + 1) == askChar) {
charCounter = charCounter + 1;
}
}
System.out.println("There are " + charCounter + " " + askChar + " in " + askPhrase);
}
}

I give credit for this answer to #Mushif, who correctly figured out the problem. Your current comparison logic is comparing a string against a character:
for (int i=0; i < askPhrase.length(); i++) {
// String char
if (askPhrase.substring(i, i + 1) == askChar) {
charCounter = charCounter + 1;
}
}
Try iterating the character set of the input word and then compare apples to apples:
for (int i=0; i < askPhrase.length(); i++) {
if (askPhrase.charAt(i) == askChar) {
charCounter = charCounter + 1;
}
}
You could also use an enhanced loop directly on the input's character set:
for (char chr : askPhrase.toCharArray()) {
if (chr == askChar) {
charCounter = charCounter + 1;
}
}

import java.util.Scanner;
public class HowManyChars {
public HowManyChars() {
Scanner sc = new Scanner (System.in);
String askPhrase;
char askChar;
char[] askChars;
int charCounter = 0;
System.out.println("Enter a phrase");
askPhrase = sc.nextLine();
askChars = askPhrase.toCharArray();
System.out.println("Enter a letter");
askChar = sc.next().charAt(0);
sc.close();
for (int i = 0; i < askChars.length; i++) {
if (Character.toLowerCase(askChar) == Character.toLowerCase(askChars[i])) {
charCounter ++;
}
}
System.out.println("There are " + charCounter + " " + askChar + " in " + askPhrase);
}
}

When I enter the value as 0 to variable val, it is not letting me take in the input through scanner

I am creating a simple project in Java to take in and display university names. When I enter the value as 0 to variable val, it is not letting me take in the input through scanner. But I can enter the value when I use val++. Please review my code and explain the logic behind this. To be specific, I am having an issue with the if (val == 0) loop.
package com.example.java;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
System.out.println("Please click to enter your name: ");
Scanner scn = new Scanner(System.in);
String str = scn.nextLine();
System.out.println("Ooh so your name is " + str);
StringBuilder sb = new StringBuilder();
System.out.println("How may universities are you expecting decisions from ");
int val = scn.nextInt();
if (val == 0) {
val++;
System.out.println("ooh nice. Enter the university you chose");
for (int i = 0; i <= val; i++) {
String waitlist = scn.nextLine();
sb.append(waitlist);
}
val--;
System.out.println("So you are going to "+sb +"!! congrats");
}
if (val >= 4) {
System.out.println("Damnnn!! " + val + " universities!! that's pretty steep");
System.out.println("Enter names of pending universities " + "\n");
for (int i = 0; i <= val; i++) {
String waitlist = scn.nextLine();
sb.append(waitlist + "\n");
}
System.out.println("So you are waiting for the following universities: " +"\n");
System.out.println(sb + "All the best mate!");
} if (val < 4 && val != 0) {
System.out.println("ooh so its just " + val + " universities, the decision should be just round the corner");
System.out.println("Enter names of pending universities " + "\n");
for (int i = 0; i <= val; i++) {
String waitlist = scn.nextLine();
sb.append(waitlist + "\n");
}
System.out.println("So you are waiting for the following universities: " +"\n");
System.out.println(sb + "All the best mate!");
}
}
}

Fixing up your number-of-universities conditions and your for-loops, something like this, still check it:
try (Scanner scn = new Scanner(System.in);) {
System.out.println("Please click to enter your name: ");
String str = scn.nextLine();
System.out.println("Ooh so your name is " + str);
System.out.println("How may universities are you expecting decisions from ");
int val = scn.nextInt();
scn.nextLine();
// 0 or negative
if (val <= 0) {
// no universities... that's pretty pessimistic
} else if (val == 1) {
System.out.println("ooh nice. Enter the university you chose");
String university = scn.nextLine();
System.out.println();
System.out.println("So you are going to " + university + "!! congrats");
} else if (val < 4) {
System.out.println("ooh so its just " + val
+ " universities, the decision should be just round the corner");
System.out.println("Enter names of pending universities: ");
StringBuilder sb = new StringBuilder();
// from i = 0 to i < val (NOT i <= val)
// 0 to val would be val iterate val + 1 times
for (int i = 0; i < val; i++) {
String waitlist = scn.nextLine();
sb.append(waitlist).append(System.lineSeparator());
}
System.out.println();
System.out.println("So you are waiting for the following universities: ");
System.out.println(sb);
System.out.println("All the best mate!");
} else if (val >= 4) {
System.out.println("Damnnn!! " + val + " universities!! that's pretty steep");
System.out.println("Enter names of pending universities: ");
StringBuilder sb = new StringBuilder();
// from i = 0 to i < val (NOT i <= val)
// 0 to val would be val iterate val + 1 times
for (int i = 0; i < val; i++) {
String waitlist = scn.nextLine();
sb.append(waitlist).append(System.lineSeparator());
}
System.out.println();
System.out.println("So you are waiting for the following universities: ");
System.out.println(sb);
System.out.println("All the best mate!");
}
}
}

Guessing letter without having to capitalize input

I am new to this and I am having hard time with this code. I made a hangman game but I am having issues with the words that have a capital letter. If I don't input a capital letter the letter will not appear.
Here is my code:
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Hangman {
static ArrayList<String> words = new ArrayList<>();
static boolean isCorrect;
private static Scanner input;
private static Scanner input2;
public static void main(String[] args) {
File filename = new File("hangman.txt");
if (!filename.exists()) {
System.out.println(filename.getAbsolutePath());
System.out.println(filename + " does not exist.");
System.exit(1);
}
try {
input2 = new Scanner(filename);
while (input2.hasNext()) {
words.add(input2.next());
}
} catch (FileNotFoundException ex) {
ex.printStackTrace();
}
input2.close();
input = new Scanner(System.in);
String playStarts = "y";
int wins = 0;
int loses = 0;
final int MAX_GUESSES = 11;
List<String> usedWords = new ArrayList<>();
while (playStarts.equals("y")) {
String word = getWord();
usedWords.add(word);
String secretWord = getSecretWord(word);
int missCount = 0;
while (!word.equals(secretWord)) {
System.out.print("(Guess) Enter a letter in word " + secretWord + " > ");
char ch = input.next().charAt(0);
if (!isAlreadyInWord(secretWord, ch)) {
secretWord = getGuess(word, secretWord, ch);
if (!isCorrect) {
System.out.print(ch + " is not in the word.");
missCount++;
System.out.println(" You missed "+ missCount + " times");
}
} else {
System.out.println(ch + " is already in word.");
}
if (missCount == MAX_GUESSES) {
System.out.println("You reached max number of guesses.");break;
}
}
if (missCount == MAX_GUESSES) {
loses++;
} else {
wins++;
}
System.out.println("The word is " + word + ". You missed " + missCount + " times");
System.out.println("Do you want to guess another word? Enter y or n >");
playStarts = input.next();
}
System.out.println("Number of wins is " + wins + ".");
System.out.println("Number of loses is " + loses + ".");
System.out.println("Used words:");
for (String word : usedWords) {
System.out.println(word);
}
input.close();
}
public static String getWord() {
return words.get((int) (Math.random() * words.size()));
}
public static String getSecretWord(String word) {
String hidden = "";
for (int i = 0; i < word.length(); i++) {
hidden += "*";
}
return hidden;
}
static public String getGuess(String word, String secretWord, char ch) {
isCorrect = false;
StringBuilder s = new StringBuilder(secretWord);
for (int i = 0; i < word.length(); i++) {
//I think the issue is in this section of the code:
if (ch == word.charAt(i) && s.charAt(i) == '*') {
isCorrect = true;
s = s.deleteCharAt(i);
s = s.insert(i, ch);
}
}
return s.toString();
}
public static boolean isAlreadyInWord(String secretWord, char ch) {
for (int i = 0; i < secretWord.length(); i++) {
if (ch == secretWord.charAt(i)) {
return true;
}
}
return false;
}
}
The code works fine but I just have an issue with the capitalization.

If your speculation be correct, the comparing the lowercase of both sides of the equation should fix the problem:
if (Character.toLowerCase(ch) == Character.toLowerCase(secretWord.charAt(i)) {
return true;
}
Better yet, you can lowercase the user character input when it actually happens:
System.out.print("(Guess) Enter a letter in word " + secretWord + " > ");
char ch = input.next().toLowerCase().charAt(0);

There are some handy functions in the Character class that you can use (Character.toUpperCase() and toLowerCase()) that can help you compare whether the characters match.
if (Character.toLowerCase(ch) == Character.toLowerCase(word.charAt(i)) && s.charAt(i) == '*') will always be checking two lowercase letters, so the case of neither ch or word.charAt(i) will matter.

beginner lexical analyzer in java

I am writing a lexical analyzer. I know it's super simple. It runs but whenever enter an input, the program treats it as invalid characters (even when they are supposed to be valid). What did I do wrong?
import java.util.*;
import java.util.Scanner;
public class LAnalyze{
public static int i;
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String s;
System.out.println("Input something to lexically analyze: ");
s = input.next( );
int j = 1;
if( s.charAt(i)!='a'||s.charAt(i)!='b'||s.charAt(i)!='c'||s.charAt(i)!='d'||s.charAt(i)!='e'||s.charAt(i)!='f'||
s.charAt(i)!='g'||s.charAt(i)!='h'||s.charAt(i)!='i'||s.charAt(i)!='j'||s.charAt(i)!='k'||s.charAt(i)!='l'||
s.charAt(i)!='m'||s.charAt(i)!='n'||s.charAt(i)!='o'||s.charAt(i)!='p'||s.charAt(i)!='q'||s.charAt(i)!='r'||
s.charAt(i)!='s'||s.charAt(i)!='t'||s.charAt(i)!='u'||s.charAt(i)!='v'||s.charAt(i)!='w'||s.charAt(i)!='x'||
s.charAt(i)!='y'||s.charAt(i)!='z'||s.charAt(i)!='A'||s.charAt(i)!='B'||s.charAt(i)!='C'||s.charAt(i)!='D'||
s.charAt(i)!='E'||s.charAt(i)!='F'||s.charAt(i)!='G'||s.charAt(i)!='H'||s.charAt(i)!='I'||s.charAt(i)!='J'||
s.charAt(i)!='K'||s.charAt(i)!='L'||s.charAt(i)!='M'||s.charAt(i)!='N'||s.charAt(i)!='O'||s.charAt(i)!='P'||
s.charAt(i)!='Q'||s.charAt(i)!='R'||s.charAt(i)!='S'||s.charAt(i)!='T'||s.charAt(i)!='U'||s.charAt(i)!='V'||
s.charAt(i)!='W'||s.charAt(i)!='X'||s.charAt(i)!='Y'||s.charAt(i)!='Z'||s.charAt(i)!='0'||s.charAt(i)!='1'||
s.charAt(i)!='2'||s.charAt(i)!='3'||s.charAt(i)!='4'||s.charAt(i)!='5'||s.charAt(i)!='6'||s.charAt(i)!='7'||
s.charAt(i)!='8'||s.charAt(i)!='9'||s.charAt(i)!='-'||s.charAt(i)!='_'||s.charAt(i)!=' ') {
for (int i = 0; i < s.length(); i++) {
System.out.println("Token " + j + " = " + (s.charAt(i)));
j++;
}
}
else {
System.out.println("Invalid character(s) entered.. Program terminated!\n");
System.exit(0);
}
}
}

It would seem that it is impossible to get the results you say you are getting from this code. Your if statement is wrong. As it currently stands, it will always be true. A character will always be not equal to some character or not equal to another character. All of the != should be ==. I would also print out the bad character in the else part that reports it:
System.out.println("bad character " + s.charAt(i) +
" decimal value: " + (int) s.charAt(i));
Scanner does lexing on its own, that is, it returns tokens, not the whole string. I think you should use Console and get everything that was typed:
Console console = System.console();
s = console.readLine("Input something to lexically analyze: ");

import java.util.*;
public class Main {
static int i;
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String s = "";
while (true) {
System.out.println("Input something to lexically analyze: ");
s = input.nextLine();
analize(s);
}
}
public static void analize(String s) {
String t = "-1234567890_ abcdefjhijklmnopqrstuvwxyzABCDEFJHIJKLMNOPQRSTUVWXYZ";
char[] tt = t.toCharArray();
char[] cc = s.toCharArray();
int z = 1, i = 0, j = 0;
for (i = 0; i < cc.length; i++) {
for (j = 0; j < tt.length; j++) {
if (cc[i] == tt[j]) {
System.out.println("Token " + z + " = '" + cc[i] + "'");
z++;
break;
}
}
if (j > tt.length - 1) {
System.out.println("Invalid character " + (i + 1) + " ('" + cc[i] + "') entered...");
}
}
}
}