Context I want to iterate over a Spark Dataset and update a HashMap for each row. Here is the code I have: Issue My issue is that the foreach doesn’t iterate at all, the lambda is never executed and I don’t know why. I implemented it as indicated here: How to traverse/iterate a Dataset in Spark Java? At the end,
Tag: foreach
Is there a way to go back by one iteration in a for-each loop?
For example, if I were to do… If it isn’t possible, is there another method of traversing through some sort of collection class while controlling the iteration counter? I tried looking through the answers to this question but couldn’t think of a way that was clear to me. Any suggestions are appreciated! Answer It depends on what you are trying
Can I run a while loop inside a for loop? [Java] If so, how would I do it in this scenario?
Im doing some simple maths using loops and my task is as follows: “Given an integer,N , print its first 10 multiples. Each multiple N * i (where 1 <= N <= ) should be printed on a new line in the form: N x i = result.” My input has to be : My output: Sample Input: Sample Output:
Does Kotlin’s version of Java’s for each have the same limitations?
I’m currently learning Kotlin coming from Java. In Java, doing for(String s:stringList){ if(condition == true) stringList.remove(s); } doesn’t work, as you can only read data with for each. Does …
Serialization process constantly overwrites itself?
I’m fairly new to java and trying to do some serialization in my project. I have a bunch of objects called Student and I would like to serialize them. The code I’m using for this is as follows: try{ …
Difference between Arraylist.forEach() and Arraylist.replaceAll()
I have a question about the difference between Arraylist.forEach() and Arraylist.replaceAll(). I know that Arraylist.forEach() is used to perform an action for each element in the list, but it seems …
How can I make my class iterable so I can use foreach syntax?
I have Book and BookList classes. BookList is something like this: public class BookList { private final List
How to avoid java.util.ConcurrentModificationException when iterating through and removing elements from an ArrayList
I have an ArrayList that I want to iterate over. While iterating over it I have to remove elements at the same time. Obviously this throws a java.util.ConcurrentModificationException. What is the best practice to handle this problem? Should I clone the list first? I remove the elements not in the loop itself but another part of the code. My code
Idiomatic way to use for-each loop given an iterator?
When the enhanced for loop (foreach loop) was added to Java, it was made to work with a target of either an array or Iterable. That works great for Collection classes that only implement one type of iteration, and thus have a single iterator() method. But I find myself incredibly frustrated the odd time I want to use a non-standard
How does the Java ‘for each’ loop work?
Consider: What would the equivalent for loop look like without using the for each syntax? Answer Note that if you need to use i.remove(); in your loop, or access the actual iterator in some way, you cannot use the for ( : ) idiom, since the actual iterator is merely inferred. As was noted by Denis Bueno, this code works