Or operand with int in if statement

Question

My problem is that program is not reading codes as i intended "he" would.

I have

if (hero.getPos() == (6 | 11 | 16)) {
    move = new Object[] {"Up", "Right", "Left"};
} else {
    move = new Object[] {"Up", "Down", "Right", "Left"};
}

When hero position is 6, the program still goes to else.

Why is that? Is it because of operands? If yes, how should i change it?

Python: if a in (1,2,5): ... If these are constants that you know of, then you can maybe do some bit trickery. If the list of numbers is large, then throw them into a set, and check if ci.getNumber() is also in that set. — Hamish Grubijan, Jan 04 '10 at 19:45
Just don't add a break -> `case 6: case 11: case 16: dosmt(); break;` — Sotirios Delimanolis, Mar 05 '13 at 16:21

score 11 · Accepted Answer · answered Mar 05 '13 at 16:15

11

Use:

if (hero.getPos() == 6 || hero.getPos() == 11 || hero.getPos() == 16)) {

This will do what you want.

What you did is comparing hero.getPos() with the result of (6|11|16) which will do bitwise or between those numbers.

answered Mar 05 '13 at 16:15

BobTheBuilder

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I was in the middle of adding it :) – BobTheBuilder Mar 05 '13 at 16:18

score 4 · Answer 2 · answered Mar 05 '13 at 17:05

The other answers are correct, just thinking differently you may use Sets.

static final Set<Integer> positions = new HashSet<Integer>();
static{
    positions.add(6);
    positions.add(11);
    positions.add(16);
}

if (positions.contains(hero.getPos())){
    move = new Object[] {"Up", "Right", "Left"};
} else {
    move = new Object[] {"Up", "Down", "Right", "Left"};
}

score 2 · Answer 3 · answered Mar 05 '13 at 16:16

You cannot do it like that. It ors the 3 number bitwise.

You have to do like this :

if (hero.getPos() == 6 || hero.getPos() == 11 | hero.getPos() == 16)) {
    move = new Object[] {"Up", "Right", "Left"};
} else {
    move = new Object[] {"Up", "Down", "Right", "Left"};
}

You see the difference ? | is a bitwise or while || is a logical or. Note also that you have to rewrite the comparison each time.

score 2 · Answer 4 · answered Mar 05 '13 at 16:20

(6 | 11 | 16) would be evaluated first to 31 (binary operation), which is 6 != 31. Not what you want.

Better is to check every single position (you have only 3, so inline is good, for more consider using a loop):

if (hero.getPos() == 6 || hero.getPos() == 11 | hero.getPos() == 16)) {
    move = new Object[] {"Up", "Right", "Left"};
} else {
    move = new Object[] {"Up", "Down", "Right", "Left"};
}

score 1 · Answer 5 · answered Jan 04 '10 at 19:46

1

No, you're going to need to check ci.getNumber() == ... for each value, or add them to a collection and check myCollection.contains(ci.getNumber()). However, you may want to re-think the structure of your code if you are checking a method against several known values.

answered Jan 04 '10 at 19:46

Jim Mitchener

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 1 · Answer 6 · edited May 23 '17 at 12:13

1

using the answer from:

How can I test if an array contains a certain value?

you could create an array of numbers and check if your ci.getNumber() is in it.

edited May 23 '17 at 12:13

Community

1
1

answered Jan 04 '10 at 19:46

John Boker

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

NawaMan · Answer 7 · 2010-01-04T21:46:08.990

1

There is no such operator. But if you are comparing number, you can use switch do simulate that. Here is how:

int aNumber = ci.getNumber();
swithc(aNumber) {
    case 6252001:
    case 5855797:
    case 6251999: {
        ...
        break;
    }
    default: {
        ... // Do else.
    }
}

Hope this helps.

edited Jan 04 '10 at 21:46

answered Jan 04 '10 at 19:47

NawaMan

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 1 · Answer 8 · edited Jan 04 '10 at 19:52

1

No. You could create a Set<Integer> once and then use that, or just:

int number = ci.getNumber();
if (number == 6252001 || number == 5855797 || number == 6251999)

I'd also consider changing those numbers into constants so that you get more meaningful code.

edited Jan 04 '10 at 19:52

Robert Harvey

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answered Jan 04 '10 at 19:47

Jon Skeet

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 1 · Answer 9 · edited Jan 16 '12 at 03:57

1

boolean theyAretheSame = num1 == num2 ? (num1 == num3 ? true:false):false;

I must admit I haven't checked this but the logic looks correct.

edited Jan 16 '12 at 03:57

Aurelio De Rosa

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answered Jan 16 '12 at 03:46

Ross

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 0 · Answer 10 · answered Jan 04 '10 at 19:46

0

You could put all the numbers in a collection, and then use the contains() method. Other than that, I don't believe there is any special syntax for comparing like you want to do.

answered Jan 04 '10 at 19:46

avpx

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 0 · Answer 11 · answered Jan 04 '10 at 19:46

0

Java won't let you do that. You can do a hash lookup (which is overkill for this) or a case statement, or a big honking ugly multiple compare:

if ((n==1 ) || (n==2) || ...

answered Jan 04 '10 at 19:46

Steve B.

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:06

score 0 · Answer 12 · answered Jan 04 '10 at 19:55

0

no.. you have to compare them individually.

answered Jan 04 '10 at 19:55

GuruKulki

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FYI: this answer merged from http://stackoverflow.com/questions/2001691/java-operators-compare-multiple-values – Shog9 Jul 24 '14 at 19:07

Or operand with int in if statement

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