What does ":" mean in this Java statement?
Solution 1
This is the Java syntax for a foreach loop.
The loop will iterate over all the items in the collection of objects returned by Season.values()
one at a time, putting each item in turn into the time
variable before executing the loop body. See this closely related question for more details on how the foreach loop works.
Solution 2
It is just a token to separate the iterating variable on the left from the array on the right in the new for-each loop
Solution 3
It's java's version of foreach
.
It's a shorthand version of
for (int i = 0; i < Season.values().size(); i++) {
Season time = Season.values().get(i);
System.out.println(time + "\t" + time.getSpan());
}
(exact details depend on what it is that Season.values() is returning, but you get the idea)
As Michael points out, while the above example is more intuitive, foreach is actually the equivalent of this:
Iterator<Season> seasons = Season.iterator();
while (seasons.hasNext()) {
Season time = seasons.next();
System.out.println(time + "\t" + time.getSpan());
}
Strawberry
I want to learn industry practices and apply them to my projects to make myself successful
Updated on June 05, 2022Comments
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Strawberry over 1 year
for (Season time : Season.values() ) system.out.println (time+ "\t" + time.getSpan());
I see an example for enumeration using
:
. What does this mean? -
Strawberry about 13 yearsOh I see. I am used to seeing
as
in PHP. -
codaddict about 13 years@Doug: in PHP you use
as
. Example:foreach($array as $val)
-
Strawberry about 13 years@codaddict yeah, I made the correcton. You're way ahead of me!
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Michael Aaron Safyan about 13 yearsActually, it is short-hand for the Iterator-based equivalent (since it works with anything that is Iterable).
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dsmith about 13 yearsIn what universe is using a for to do an indexed iteration over a container more intuitive than using Iterator semantics. Each to their own I suppose..
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Brad Mace about 13 years@dsmith - when I say "more intuitive", I meant in terms of explaining what foreach does. Since it's still structured as a
for
-loop, I think it's easier for people to relate what's going on if they're seeing a for-each construct for the first time