Arrays in Swift support the += operator to add the contents of one Array to another. Is there an easy way to do that for a dictionary? eg: var dict1 = [“a” : “foo”] var dict2 = [“b” : “bar”] var combinedDict = … (some way of combining dict1 & dict2 without looping) 28 Answers … Read more
I have a very simple task I am trying to do in Groovy but cannot seem to get it to work. I am just trying to loop through a map object in groovy and print out the key and value but this code does not work. // A simple map def map = [ iPhone … Read more
For example I have a list of strings like: val list = listOf(“a”, “b”, “c”, “d”) and I want to convert it to a map, where the strings are the keys. I know I should use the .toMap() function, but I don’t know how, and I haven’t seen any examples of it. 6 Answers 6
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations. Closed 7 years ago. Improve this question I am writing a program that … Read more
I know a map is a data structure that maps keys to values. Isn’t a dictionary the same? What is the difference between a map and a dictionary1? 1. I am not asking for how they are defined in language X or Y (which seems to be what generally people are asking here on SO), … Read more
I am a little confused on the answer that Xcode is giving me to this experiment in the Swift Programming Language Guide: // Use a for-in to iterate through a dictionary (experiment) let interestingNumbers = [ “Prime”: [2, 3, 5, 7, 11, 13], “Fibonacci”: [1, 1, 2, 3, 5, 8], “Square”: [1, 4, 9, 16, … Read more
I have a map: var sessions = map[string] chan int{} How do I delete sessions[key]? I tried: sessions[key] = nil,false; That didn’t work. Update (November 2011): The special syntax for deleting map entries is removed in Go version 1: Go 1 will remove the special map assignment and introduce a new built-in function, delete: delete(m, … Read more
I’d like to get from this: keys = [1,2,3] to this: {1: None, 2: None, 3: None} Is there a pythonic way of doing it? This is an ugly way to do it: >>> keys = [1,2,3] >>> dict([(1,2)]) {1: 2} >>> dict(zip(keys, [None]*len(keys))) {1: None, 2: None, 3: None} 7 Answers 7
Given the following code interface IPerson { firstName: string; lastName: string; } var persons: { [id: string]: IPerson; } = { “p1”: { firstName: “F1”, lastName: “L1” }, “p2”: { firstName: “F2″ } }; Why isn’t the initialization rejected? After all, the second object does not have the “lastName” property. 6 Answers 6
I know I can iterate over a map m by, for k, v := range m { … } and look for a key but is there a more efficient way of testing a key’s existence in a map? I couldn’t find the answer in the language spec. 1Best Answer 11 recommended by Go Language
