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I am writing a class in which there is a method (acceptSelection) that accepts a user move as a string of type "A3", "B4" and the like. In this method, the character is separated from the number. As a result, four variables are obtained: word1, number1, word2, word2, which are string and numeric representations of the user course, respectively. That is, let's say, there were moves A3 and B4, so word1 = "A", word2 = "B", number1 = 3, number2 = 4. After that, it is necessary to determine their indices in the array from the method (getScore).

public class ExampleOne { private static int number1; private static int number2; private static String word1; private static String word2; private static int index1; private static int index2; private static String a3 = "A3"; private static String b4 = "B4"; public static void main (String args[]) { acceptSelection(a3, b4); System.out.println("Index 1 " + index1); System.out.println("Index 2 " + index2); } public static int getScore (String df, int b) { int totalScore=0; if (a=="A") { totalScore = (0+b)-1; //return totalScore; } else if (a=="B") { totalScore = (4+b)-1; //return totalScore; } else if (a=="C") { totalScore = (8+b)-1; //return totalScore; } else if (a=="D") { totalScore = (12+b)-1; //return totalScore; } else if (a=="E") { totalScore = (16+b)-1; //return totalScore; } else if (a=="F") { totalScore = (20+b)-1; //return totalScore; } else if (a=="G") { totalScore = (24+b)-1; //return totalScore; } return totalScore; } public static void acceptSelection (String a, String b) { Pattern number = Pattern.compile("[0-9]"); Matcher m = number.matcher(a); Matcher m1 = number.matcher(b); while (m.find()) { number1 =Integer.parseInt(a.substring(m.start(), m.end())); } while (m1.find()) { number2 =Integer.parseInt(b.substring(m1.start(), m1.end())); } Pattern word = Pattern.compile("[a-zA-Z]"); Matcher w = word.matcher(a); Matcher w1 = word.matcher(b); while (w.find()) { word1 = a.substring(w.start() , w.end()); } while (w1.find()) { word2 = b.substring(w1.start() , w1.end()); } index1 = getScore(word1, number1); index2 = getScore(word2, number2); }

When the getScore method is called in this way, index1 = getScore (word1, number1), a zero totalScore is returned. However, if you call the method like this: index1 = getScore ("A", 3) everything works correctly. I can not understand what the problem is. It seems that the problem lies in the simple, just can not see.

Reported as a duplicate by participants pavlofff , Alexey Shimansky , Lex Hobbit ,, mymedia Nov 2, '17 at 5:10 pm .

A similar question was asked earlier and an answer has already been received. If the answers provided are not exhaustive, please ask a new question .

  • Duck, I understand that it does not meet the conditions, but I ask why this condition does not pass? When testing variables using the console output method, it works correctly. If in the method I output the word1 variable via prinln, the correct string is output to the console. - Ayrat
  • Put a breakpoint at the beginning. Enable code in debug mode. See how your program works in steps. Looking for mistakes. Profit - ArchDemon
  • The lines are compared through the operator equals() , not == : for example, a.equals("A") will work this way, but I would recommend that you completely rework all this code, it is terrible (nothing personal) - pavlofff
  • Thanks, it worked. What about when I consider. If there is any kind of literature about this - tell me. - Ayrat
  • Any Java textbooks from recognized authors: B.Ekkel, G.Shildt, K.Hortstsmann .. - pavlofff

1 answer 1

I suggest the same, but somewhat simpler.

UPD : and a few more simple:

 public class ExampleOne { private static String a3 = "A3"; private static String b4 = "B4"; public static void main(String args[]) { System.out.println("Index 1 " + acceptSelection(a3)); System.out.println("Index 2 " + acceptSelection(b4)); } public static int getScore(char ch, int num) { int code = (int)ch; return (code-65)*4+num-1; } public static int acceptSelection(String str) { char word = str.charAt(0); int number = Character.getNumericValue(str.charAt(1)); return getScore( word, number); } }
  • Interesting. Thank you very much, I will test) - Ayrat