I have the following code to do this, but how can I do it better? Right now I think it’s better than nested loops, but it starts to get Perl-one-linerish when you have a generator in a list comprehension. day_count = (end_date – start_date).days + 1 for single_date in [d for d in (start_date + … Read more
What is the most basic definition of “iterable”, “iterator” and “iteration” in Python? I have read multiple definitions but I am unable to identify the exact meaning as it still won’t sink in. Can someone please help me with the 3 definitions in layman terms? 18 s 18 Iteration is a general term for taking … Read more
In C++, I can iterate over an std::string like this: std::string str = “Hello World!”; for (int i = 0; i < str.length(); ++i) { std::cout << str[i] << std::endl; } How do I iterate over a string in Python? 9 s 9 As Johannes pointed out, for c in “string”: #do something with c … Read more
I have an object in JavaScript: { abc: ‘…’, bca: ‘…’, zzz: ‘…’, xxx: ‘…’, ccc: ‘…’, // … } I want to use a for loop to get its properties. And I want to iterate it in parts (not all object properties at once). With a simple array I can do it with a … Read more
Being somewhat new to the Java language I’m trying to familiarize myself with all the ways (or at least the non-pathological ones) that one might iterate through a list (or perhaps other collections) and the advantages or disadvantages of each. Given a List<E> list object, I know of the following ways to loop through all … Read more
This question’s answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. I’m iterating over a list of tuples in Python, and am attempting to remove them if they meet certain criteria. for tup in somelist: if determine(tup): code_to_remove_tup What should I use in … Read more
We all know you can’t do the following because of ConcurrentModificationException: for (Object i : l) { if (condition(i)) { l.remove(i); } } But this apparently works sometimes, but not always. Here’s some specific code: public static void main(String[] args) { Collection<Integer> l = new ArrayList<>(); for (int i = 0; i < 10; ++i) … Read more
I’ve been told not to use for…in with arrays in JavaScript. Why not? 2 27 The reason is that one construct: var a = []; // Create a new empty array. a[5] = 5; // Perfectly legal JavaScript that resizes the array. for (var i = 0; i < a.length; i++) { // Iterate over … Read more
Let me prefix this by saying that I know what foreach is, does and how to use it. This question concerns how it works under the bonnet, and I don’t want any answers along the lines of “this is how you loop an array with foreach“. For a long time I assumed that foreach worked … Read more
This question already has answers here: How do I efficiently iterate over each entry in a Java Map? (46 answers) Closed 2 years ago. What’s the best way to iterate over the items in a HashMap? 7 If you’re only interested in the keys, you can iterate through the keySet() of the map: Map<String, Object> … Read more
