If comparison in Java miss

Question

I have a portion of code that should do that: 1) Take the name of a color from keyboard 2) Give that color to an object in wich i have another object declaration 3) Decrement from 2 to 1 the correspondant line of the array of 2.

In the main class i want to memorize the color in a variable TemporaryColor.

Scanner input = new Scanner(System.in);
String TemporaryColor = input.nextLine();
playerOrd[1].DecrementoSegnalino(TemporaryColor);

playerOrd is a class that contains this method:

public void DecrementoSegnalino(String color) {
    SegnalinoScommessaGiocatore.decrementaSegnaliniScommessa(color);    
}

SegnalinoScommessaGiocatore have this array:

private int[] numeroSegnaliniScommessa = {2,2,2,2,2,2};

and this method:

public void decrementaSegnaliniScommessa(String color) {
    if (color.equalsIgnoreCase("Black") numeroSegnaliniScommessa[0]--;
    if (color.equalsIgnoreCase("Blue") numeroSegnaliniScommessa[1]--;
    if (color.equalsIgnoreCase("Green") numeroSegnaliniScommessa[2]--;
    if (color.qualsIgnoreCase("Red") numeroSegnaliniScommessa[3]--;
    if (color.equalsIgnoreCase("Yellow") numeroSegnaliniScommessa[4]--;
    if (color.equalsIgnoreCase("White") ) numeroSegnaliniScommessa[5]--;    
    }

There is a problem passing the string that i write with Keyboard... If i use this in the beginning:

playerOrd[1].DecrementoSegnalino("Black");

It works!

What's the problem?

score 1 · Accepted Answer · answered Jun 15 '13 at 22:52

1

Don't compare Strings using ==. Use the equals(...) or the equalsIgnoreCase(...) method instead. Understand that == checks if the two objects are the same which is not what you're interested in. The methods on the other hand check if the two Strings have the same characters in the same order, and that's what matters here. So instead of

if (fu == "bar") {
  // do something
}

do,

if ("bar".equals(fu)) {
  // do something
}

or,

if ("bar".equalsIgnoreCase(fu)) {
  // do something
}

answered Jun 15 '13 at 22:52

Hovercraft Full Of Eels

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Made community wiki because this has been asked and answered many many times. – Hovercraft Full Of Eels Jun 15 '13 at 22:53
I pasted old code before. I used equals (i edited the post) but the problem sussists! As i said, if i write: playerOrd[1].DecrementoSegnalino("Black"); The comparison is succesfull – Pittogatto Jun 15 '13 at 23:01

If comparison in Java miss

1 Answers1