For loop what does this mean?

Question

i'm learning Java at the moment and am learning how to parse HTML.

i understand how for loops work

For example:

for(int i = 0; i < 20; i++){
}

means that i is 0, if i is less than 20 then increase by 1.

But what does this mean????

for(Element newsHeadline: newsHeadlines){
                    System.out.println(newsHeadline.attr("href"));
                }

i have tried googleing this but can't find answer

Thanks

possible duplicate of [How does the Java for each loop work?](http://stackoverflow.com/questions/85190/how-does-the-java-for-each-loop-work) — Biffen, Feb 10 '15 at 07:24
^^ Checkout aliteralmind's answer in that thread as it goes into detail about syntax and how to use. — Antony D'Andrea, Feb 10 '15 at 07:29

score 2 · Answer 1 · answered Feb 10 '15 at 07:25

This is a foreach loop.

newsHeadlines is an array of objects of type Element.

for(Element newsHeadline: newsHeadlines)

Should be read as

For each newsHeadline in newsHeadlines do

It will end after it reaches the last object of newsHeadlines and finishes the code in the block.

Hopefully now that you know it is a foreach loop, it will help you refine your Google search.

score 1 · Answer 2 · answered Feb 10 '15 at 07:24

1

It's a for-each loop. It uses iterator to iterate over collection

https://docs.oracle.com/javase/1.5.0/docs/guide/language/foreach.html

answered Feb 10 '15 at 07:24

euclid135

1,262
2
16
23

score 1 · Answer 3 · answered Feb 10 '15 at 07:28

For loop is a short form of original for loop, but without index of given element.

As an example:

for(Element newsHeadline: newsHeadlines){
   System.out.println(newsHeadline.attr("href"));
}

is same as:

Iterator<Element> it  = newsHeadlines.iterator();
while(it.hasNext()){
   Element newsHeadline = it.next();
   System.out.println(newsHeadline.attr("href"));
}

As you can see it is shorter and more readable. In short it means: for every element in collection do something. You can iterate over any iterable collection or array.

score 1 · Answer 4 · answered Feb 10 '15 at 07:28

It is for-each loop. It is shorthand for writing for loop eliminating the use of index.

String[] names = {"Alex", "Adam"};

for(int i = 0; i < names.length; i ++) {
    System.out.println(names[i]);
}

for(String name: names) {
    System.out.println(name);
}

score 0 · Answer 5 · edited May 23 '17 at 11:51

0

This is an iterating loop: each iteration puts the next element of the collection newsHeadlines inside newsHeadline. Checkout this thread: How does the Java 'for each' loop work?

edited May 23 '17 at 11:51

Community

1
1

answered Feb 10 '15 at 07:25

baryo

1,441
13
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score 0 · Answer 6 · answered Feb 10 '15 at 07:31

I think it will help you.

Example:

public class Test {

   public static void main(String args[]){
      int [] numbers = {10, 20, 30, 40, 50};

      for(int x : numbers ){
         System.out.print( x );
         System.out.print(",");
      }
      System.out.print("\n");
      String [] names ={"James", "Larry", "Tom", "Lacy"};
      for( String name : names ) {
         System.out.print( name );
         System.out.print(",");
      }
   }
}
This would produce the following result:

10,20,30,40,50,
James,Larry,Tom,Lacy,

For loop what does this mean?

6 Answers6