Calling str(…) is the Pythonic way to convert something to a string. You might want to consider why you want a list of strings. You could instead keep it as a list of integers and only convert the integers to strings when you need to display them. For example, if you have a list of … Read more
You could try this: List<Int32> copy = new List<Int32>(original); or if you’re using C# 3 and .NET 3.5, with Linq, you can do this: List<Int32> copy = original.ToList(); I see that this answer is still getting upvotes. Well, here’s a secret for ya: the above answer is still using a foreach. Please don’t upvote this … Read more
c# 7.0 lets you do this: var tupleList = new List<(int, string)> { (1, “cow”), (5, “chickens”), (1, “airplane”) }; If you don’t need a List, but just an array, you can do: var tupleList = new(int, string)[] { (1, “cow”), (5, “chickens”), (1, “airplane”) }; And if you don’t like “Item1” and “Item2”, you … Read more
If you don’t have any other indexes or sorted information for your objects, then you will have to iterate until such an object is found: next(obj for obj in objs if obj.val == 5) This is however faster than a complete list comprehension. Compare these two: [i for i in xrange(100000) if i == 1000][0] … Read more
ES6 (ES2015) and up If you’re using ECMAScript 6 (a.k.a. ES2015) or higher, the cleanest way is to construct an array of the items and use Array.includes: [‘a’, ‘b’, ‘c’].includes(‘b’) This has some inherent benefits over indexOf because it can properly test for the presence of NaN in the list, and can match missing array … Read more
Try SelectMany() var result = iList.SelectMany( i => i );
Try using a list comprehension and a conditional expression. >>> a=[1,2,3,1,3,2,1,1] >>> [4 if x==1 else x for x in a] [4, 2, 3, 4, 3, 2, 4, 4]
I suggest that you use a profiler to test which is faster. My personal opinion is that you should use Lists. I work on a large codebase and a previous group of developers used arrays everywhere. It made the code very inflexible. After changing large chunks of it to Lists we noticed no difference in … Read more
Legacy. List was originally defined to be functional-languages-looking: 1 :: 2 :: Nil // a list list1 ::: list2 // concatenation of two lists list match { case head :: tail => “non-empty” case Nil => “empty” } Of course, Scala evolved other collections, in an ad-hoc manner. When 2.8 came out, the collections were … Read more
Use an Iterator and call remove(): Iterator<String> iter = myArrayList.iterator(); while (iter.hasNext()) { String str = iter.next(); if (someCondition) iter.remove(); }