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Java

Stacy Chambers
Stacy Chambers
1,179 Points
Posted by Stacy Chambers
Stacy Chambers
1,179 Points

For Loops for (BlogPost post: mPosts)

Can someone explain this type of for loop or help me find where the track is that explains for loops. I need to review.

1 Answer

gyorgyandorka
gyorgyandorka
13,811 Points
gyorgyandorka
gyorgyandorka
13,811 Points

This is a so-called for each loop.

The syntax in Java looks like this:

for (Type item : someCollectionOfItems) { 
    // do this stuff in each cycle 
}
  • the loop will run n cycles where n is the size of someCollection
  • item: a newly declared variable which will be assigned to the i-th item in the collection in the i-th cycle of the loop
  • someCollection: the collection (an iterable object) you'd like to iterate through from the first to last element

You can achieve the same with a regular for loop, the difference is that inside the loop body you cannot directy refer to the elements in the collection, only via their indexes:

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

// with a for each loop you can use the 'item' variable as an alias for the current item:
for (String item : anArrayListOfStrings) { 
    System.out.println(item);
}