Set Array Items in Method Parameter

Question

I would like to set the items in an array of Strings in the parameter of a method.

So if I have an array, public String[] messages;

Then I have a method, public void setMessages(),

I want to be able to use the parameters to set the items in the array, like this:

public void setMessages(String[] messages) {
   this.messages = messages;
}

setMessages("Message 1", "Message 2", "Message 3");

And then the array has those three strings in it. How could I do something like this, because that obviously doesn't work?

Juned Ahsan · Accepted Answer · 2013-11-09 06:05:23Z

2

Your setMessages method accepts an array and not three String parameters as mentioned here:

public void setMessages(String[] messages)

So you need to pass an array to it. Simply replace

setMessages("Message 1", "Message 2", "Message 3");

with

setMessages(new String[] {"Message 1", "Message 2", "Message 3"});

answered Nov 9, 2013 at 6:05

Juned Ahsan

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1 Comment

+1 I like new String[]{} better than varargs. I recently got burned with varargs causing an ambiguous signature.

Makoto · Accepted Answer · 2013-11-09 06:05:23Z

-1

Change your method signature to accept messages as a variable-length argument, or vararg for short.

public void setMessages(String... messages) {
    this.messages = messages;
}

What are varargs?

They are equivalent to an array of the same type (so above, you still have a String[]).
They allow any arbitrary number of values to be placed into it.
They do not require the caller to create a new instance of an array to pass in (which would look like this):
```
 setMessages(new String[] {"Message 1", "Message 2", "Message 3"});
```

answered Nov 9, 2013 at 6:05

Makoto

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