JAVA lang question.

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John.Leonard@_remove_before_sending_gmail.com - 09 Jan 2008 21:55 GMT

Hello,

What does "String a : args" mean in the following code snippet:

public class FindDups {
public static void main(String[] args) {
Set<String> s = new HashSet<String>();
for (String a : args)
if (!s.add(a))
System.out.println("Duplicate detected: " + a);

System.out.println(s.size() + " distinct words: " + s);
}
}

J Leonard

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Joe Attardi - 09 Jan 2008 22:20 GMT

> Hello,
>
[quoted text clipped - 10 lines]
> }
> }

It's the new (as of Java 5) for-loop syntax. It iterates over the array
args, assigning each String in the iteration to the variable a.

Basically, this:

for (String a : args) {
...
}

is equivalent to:

for (int n = 0; n < args.length; n++) {
String a = args[n];
...
}

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rossum - 09 Jan 2008 23:13 GMT

On Wed, 9 Jan 2008 13:55:22 -0800 (PST),
"John.Leonard@_remove_before_sending_gmail.com"
<John.Richard.Leonard@gmail.com> wrote:

>Hello,
>
[quoted text clipped - 12 lines]
>
>J Leonard

It is a foreach loop, which sets s to each String in args in turn.
Think of it as:

foreach (String s in args) {
doSomethingWith(s);
}

The Java powers that be did not want to mess about with adding new
keywords, so "foreach" stayed as "for" and "in" became ':', so:

for (String s : args) {
doSomethingWith(s);
}

rossum

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JAVA lang question.

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