CODEWITHSUNDEEP
javaarraysobject
iPherian
iPherian

Reputation: 958

Initialize array of custom class

I'd like to initialize an array of objects (contrived example)

class StringPair {
    String a;
    String b;
    // constructor
}

StringPair p[] = {
    { "a", "b" },
    { "c", "d" }
};

But javac complains java: illegal initializer for StringPair for definition of p

How should I write this?

Upvotes: 4

Views: 3175

Answers (7)

Jamie
Jamie

Reputation: 1922

I don't know why so many people keep posting the same solution.

In my case, I needed to initialize an array of objects. However, these objects were generated from XSD, so I'm not able to add a custom constructor. We'd need C# with partial classes for that.

Pau above gave me the hint to solve it, but his solution doesn't compile. Here's one that does:

StringPair p[] = new StringPair[] {
    new StringPair(){{
      setA("a");
      setB("b");
    }},
     new StringPair(){{
      setA("c");
      setB("d");
    }}
};

Upvotes: 0

Pau
Pau

Reputation: 16106

If you are not able to create a constructor with params, you could use double brace initialization:

StringPair p[] = {
    new StringPair(){{
      setA("a");
      setB("b");
    }},
     new StringPair(){{
      setA("c");
      setB("d");
    }}
};

It seems like something you are looking for.

Upvotes: 1

Ashok Rayal
Ashok Rayal

Reputation: 405

You should Create a constructor like this

class StringPair {
String a;
String b;

Public StringPair(string a, string b)
{
this.a=a;
this.b=b;
}
}

then you can initialize it like this 

StringPair p[] = { new StringPair("a", "b"), new StringPair("c", "d") };

Upvotes: 0

Chetan Joshi
Chetan Joshi

Reputation: 5711

You need to pass object's of StringPair

like below code

StringPair p[] = { new StringPair ("a", "b"), new StringPair ("c", "d") };

Upvotes: 0

ΦXocę 웃 Пepeúpa ツ
ΦXocę 웃 Пepeúpa ツ

Reputation: 48278

following list initialization (name taken from C++) is not a valid java way to init an array:

StringPair p[] = {
    { "a", "b" },
    { "c", "d" }
};

do instead use the constructor of your class:

StringPair p[] = { new StringPair("a", "b"), new StringPair("1", "g") };

Upvotes: 0

sovas
sovas

Reputation: 1578

Use new Operator inside {}. difference between object and variable

StringPair p[] = {
    new StringPair("a", "b"),
    new StringPair("c", "d")
};

Upvotes: 2

Eran
Eran

Reputation: 393856

You should invoke the constructor :

StringPair[] p = { new StringPair ("a", "b"), new StringPair ("c", "d") };

Upvotes: 6

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