Constructor using multiple arrays in java

Question

Having trouble creating a constructor that takes multiple one dimensional arrays of Strings:

class relation {

String[] setA, setB, setC;

relation (String[] setA, String[] setB, String[] setC) {
    this.setA = setA;
    this.setB = setB;
    this.setC = setC;
} 
}

public class matrix {

public static void main(String[] args) {

    relation relation1 = new relation({"1","2","3","4","5"}, {"1","2","3","4"}, {"2","3","4","5"});
    relation relation2 = new relation({"a","b","c","d"}, {"a","b","c","d","b","c"}, {"a","b","c","d","c","b"});

}

}

I keep getting multiple errors - Syntax error on token(s), misplaced construct(s) - Type mismatch: cannot convert from String[] to relation - Syntax error on token "}", delete this token - Syntax error on token ")", } expected

I need to be able to use each array separately withing the relation class.

It's off-topic here, but normally, in java, we write class names in CamelCase — Daniel Alder
– Daniel Alder, Commented Jun 4, 2015 at 7:59

Mureinik · Accepted Answer · 2015-06-04 07:52:44Z

5

You can't use array literals that way in Java - you have to explicitly initialize them. e.g.:

relation relation1 = new relation(new String[]{"1","2","3","4","5"}, 
                                  new String[]{"1","2","3","4"},
                                  new String[]{"2","3","4","5"});

answered Jun 4, 2015 at 7:52

Mureinik

316k54 gold badges402 silver badges406 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Chetan Kinger Over a year ago

Note that String []arr = {"1","2"}; is still allowed.

Mureinik Over a year ago

@ChetanKinger yup, but that's the only place it'll fly

Chetan Kinger Over a year ago

@Mureinik True. The compiler replaces it with String []arr = new String[]{"1","2"}; I wonder why the limitation was imposed on using the same shorthand for arguments. Also, I prefer using varargs over an array as a parameter in such situations.

TheCodingFrog · Accepted Answer · 2015-06-04 08:01:02Z

1

You can do it like this -

class Relation {
    String[] setA, setB, setC;
    Relation(String[] setA, String[] setB, String[] setC) {
        this.setA = setA;
        this.setB = setB;
        this.setC = setC;
    }
}

public class Assignment3 {

    public static void main(String[] args) {
        Relation relation1 = new Relation(
                new String[]{"1", "2", "3", "4", "5"}, new String[]{"1", "2",
                        "3", "4"}, new String[]{"2", "3", "4", "5"});
        Relation relation2 = new Relation(new String[]{"a", "b", "c", "d"},
                new String[]{"a", "b", "c", "d", "b", "c"}, new String[]{"a",
                        "b", "c", "d", "c", "b"});
    }
}

answered Jun 4, 2015 at 8:01

TheCodingFrog

3,5343 gold badges24 silver badges27 bronze badges

2 Comments

Chetan Kinger Over a year ago

Nicely formatted. Other than that, does not add much value over the accepted answer. Especially when it is posted 7 minutes later..

TheCodingFrog Over a year ago

Yes - agree nicely fomatted and follow Java naming conventions.

Priyesh · Accepted Answer · 2015-06-04 13:20:41Z

1

Try like this it will work

relation relation1 = new relation(new String[]{"1","2","3","4","5"},
                        new String[]{"1","2","3","4"},new String[]{"2","3","4","5"});

edited Jun 4, 2015 at 13:20

Priyesh

2,0811 gold badge18 silver badges26 bronze badges

answered Jun 4, 2015 at 12:51

Ranga Raju

111 bronze badge

Collectives™ on Stack Overflow

Constructor using multiple arrays in java

3 Answers 3

3 Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related