I have the following piece of string: 'username=Tomas&password=123', I've tried to split the string into 2 parts then split it again to remove the equals sign but don't know how to load that into a dictionary
Once you've split the components, you can split again inside reduce() and assign to the object. You could also do this in a for loop if you don't want to use reduce().
let str = 'username=Tomas&password=123'
let components = str.split('&') // [ 'username=Tomas', 'password=123' ]
let dict = components.reduce((obj, comp) => {
let [key, val] = comp.split('=') // ['username', 'Tomas']
obj[key] = val
return obj
}, {})
console.log(dict)
Related
I have a multidimensional object and using Vue, I am trying to make the inner object reactive.
My object looks like this:
data() {
return {
myObject: {}
}
}
And the filled data looks like this:
myObject: {
1: { // (client)
0: "X", // (index) : (value)
1: "Y"
},
2: {
0: "A",
2: "B"
}
}
If I try using:
let value = "X";
let client = 1;
let index = 1;
let obj = {};
obj[client][index] = value;
this.myObject = Object.assign({}, this.myObject, obj);
It throws an error:
TypeError: Cannot set property '0' of undefined
And if I try below, it overwrites the initial values as it is initially setting the object to {}
let obj = {};
obj[index] = value;
let parentObj = {};
parentObj[client] = obj;
this.myObject = Object.assign({}, this.myObject, parentObj);
What is the proper way of adding the values to the multidimensional object?
In javascript, dim2Thing[1][1] = ... expressions require dim2Thing[1] to exist. This is why you get the error you mentioned. So you can do two expressions, which should work fine:
dim2Thing[1] = dim2Thing[1] || {}
dim2Thing[1][1] = otherThing
For the last block, you mention that it "overwrites the initial values"
I think what's actually happening here is just that Object.assign is not recursive. It only merges top-level keys. So if parentObj has a key that over-laps with this.myObj, then sub-keys will be lost.
Object.assign({ a: { b: 2} }, { a: { c: 3 } }) // returns { a: { c: 3 } }
This is what I interpret your code as trying to do - though I am unfamiliar with vue.js at this time, so I cannot assure it will have the desired result to your webpage:
let value = "X";
let client = 1;
let index = 1;
const newObj = Object.assign({}, this.myObject);
// if you have lodash _.set is handy
newObj[client] = newObj[client] || {}; // whatever was there, or a new object
newObj[client][index] = value
this.myObject = newObj
Just use an array, thats reactive by design.
If you need to get elements from the array in your template or anywhere just add a find method
// temp
late
<div v-for="(value, idx) in myArray">{{find(obj => obj.id === idx)}}</div>
methods: {
find (searchFunction) {
return this.myArray.find(searchFunction)
}
}
I have a huge text in String.
For example "... value=word. ...". How can I get the string "word" if I know that before I have "value=" and after "."?
for example:
for str in string {
if str == "value=" {
// then get the strings until .
}
}
Thanks!
You can extend String with a kind of sliceBetween method:
import Foundation
extension String {
func sliceFrom(start: String, to: String) -> String? {
guard let s = rangeOfString(start)?.endIndex else { return nil }
guard let e = rangeOfString(to, range: s..<endIndex)?.startIndex else { return nil }
return self[s..<e]
}
}
And you'd use it like this:
"... value=word. ...".sliceFrom("value=", to: ". ") // "word"
NSRegularExpression should solve your issue.
In order to use it, you will need to understand Regex first. In your case, you can use value=[\\w]+[^.]+ as your regex pattern.
The following code will give you a [String] object contains value=allCharacterBeforeFirstPeriod
let regex = try NSRegularExpression(pattern: "value=[\\w]+[^.]+", options: [])
let nsStr = str as NSString
let array = regex.matchesInString(str, options: [], range: NSMakeRange(0, nsStr.length))
let results = array.map({ nsStr.substringWithRange($0.range) })
And then if you only need the value after value=, you can use another map function to do it:
results.map({ $0.stringByReplacingOccurrencesOfString("value=", withString: "") })
I have tested the code with a 10,000 characters String. It finishes in ~0.3 sec
The most straight forward way to do this would be to use NSRegularExpression. Tutorial
Given an input String like this
let text = "key0=value0&key1=value1&key2=value2"
You can organireduce method
let dict = text.characters.split("&").reduce([String:String]()) { (var result, keyValue) -> [String:String] in
let chunks = keyValue.split("=")
guard let first = chunks.first, last = chunks.last else { return result }
let key = String(first)
let value = String(last)
result[key] = value
return result
}
Now everything is stored inside dict and you can easily access it
dict["key2"] // "value2"
Given a string, how do I truncate all characters following one particular character?
For example I have a url:
http://pics.v6.top.rbk.ru/v6_top_pics/resized/250xH/media/img/7/92/754435534528927.jpg"><div>Some text</div>"
I want to strip all characters after the ", including the " character.
extension String {
mutating func stripFromCharacter(char:String) {
let c = self.characters
if let ix = c.indexOf("\"") {
self = String(c.prefixUpTo(ix))
}
}
}
And here's how to use it:
var s = "http://pics.v6.top.rbk.ru/v6_top_pics/resized/250xH/media/img/7/92/754435534528927.jpg\"><div>Some text</div>"
s.stripFromCharacter("\"")
Probably the dumbest way to do it but it works.
let a = "http://pics.v6.top.rbk.ru/v6_top_pics/resized/250xH/media/img/7/92/754435534528927.jpg\"" + "><div>Some text</div>"
print(a)
var new = ""
for char in a.characters{
if char == "\""{ break }
new.append(char)
}
print(new)
Maybe you simply want to use NSDataDetectors?
E.G. something like:
let input = "http://pics.v6.top.rbk.ru/v6_top_pics/resized/250xH/media/img/7/92/754435534528927.jpg"><div>Some text</div>""
let detector = try! NSDataDetector(types: NSTextCheckingType.Link.rawValue)
let matches = detector.matchesInString(input, options: [], range: NSMakeRange(0, input.characters.count))
for match in matches {
let url = (input as NSString).substringWithRange(match.range)
print(url)
}
More info can be found in this HackingWithSwift blog post.
let str = "tHIS is A test"
let swapped_case = "This IS a TEST"
Swift noob here, how to do the second statement programatically?
This function works with all upper/lowercase characters
defined in Unicode, even those from "foreign" languages such as Ä or ć:
func swapCases(_ str : String) -> String {
var result = ""
for c in str.characters { // Swift 1: for c in str {
let s = String(c)
let lo = s.lowercased() //Swift 1 & 2: s.lowercaseString
let up = s.uppercased() //Swift 1 & 2: s.uppercaseString
result += (s == lo) ? up : lo
}
return result
}
Example:
let str = "tHIS is a test ÄöÜ ĂćŒ Α" // The last character is a capital Greek Alpha
let swapped_case = swapCases(str)
print(swapped_case)
// This IS A TEST äÖü ăĆœ α
Use switch statement in-range checks to determine letter case, and use NSString-bridged methods to convert accordingly.
let str = "tHIS is A test"
let swapped_case = "This IS a TEST"
func swapCase(string: String) -> String {
var swappedCaseString: String = ""
for character in string {
switch character {
case "a"..."z":
let uppercaseCharacter = (String(character) as NSString).uppercaseString
swappedCaseString += uppercaseCharacter
case "A"..."Z":
let lowercaseCharacter = (String(character) as NSString).lowercaseString
swappedCaseString += lowercaseCharacter
default:
swappedCaseString += String(character)
}
}
return swappedCaseString
}
swapCase(str)
I'm a bit too late but this works too :-)
let str = "tHIS is A test"
var res = ""
for c in str {
if contains("ABCDEFGHIJKLMNOPQRSTUVWXYZ", c) {
res += "\(c)".lowercaseString
} else {
res += "\(c)".uppercaseString
}
}
res
In Swift 5 I achieved it by creating a function which iterates through each character of the string, and using string methods to change each character I appended each character back into a new variable:
func reverseCase(string: String) -> String {
var newCase = ""
for char in string {
if char.isLowercase {
newCase.append(char.uppercased())
}
else if char.isUppercase {
newCase.append(char.lowercased())
}
else {
newCase.append(char)
}
}
return newCase
}
Then just pass your string through to the function when you call it in a print statement:
print(reverseCase(string: str))
You already have plenty of good succinct answers but here’s an over-elaborate one for fun.
Really this is a job for map – iterate over a collection (in this case String) and do a thing to each element (here, each Character). Except map takes any collection, but only gives you back an array, which you’d have to then turn into a String again.
But here’s a version of map that, given an extensible collection, gives you back that same kind of extensible collection.
(It does have the limitation of needing both collections to contain the same type, but that’s fine for strings. You could make it return a different type, but then you’d have to tell it which type you wanted i.e. map(s, transform) as String which would be annoying)
func map<C: ExtensibleCollectionType>(source: C, transform: (C.Generator.Element) -> C.Generator.Element) -> C {
var result = C()
for elem in source {
result.append(transform(elem))
}
return result
}
Then to write the transform function, first here’s an extension to character similar to the other answers. It does seem quite unsatisfying that you have to convert to a string just to uppercase a character, is there really no good (international characterset-friendly) way to do this?
extension Character {
var uppercaseCharacter: Character {
let s = String(self).uppercaseString
return s[s.startIndex]
}
var lowercaseCharacter: Character {
let s = String(self).lowercaseString
return s[s.startIndex]
}
}
And the function to flip the case. What I wonder is whether this pattern matching is international-friendly. It seems to be – "A"..."Z" ~= "Ä" returns true.
func flipCase(c: Character) -> Character {
switch c {
case "A"..."Z":
return c.lowercaseCharacter
case "a"..."z":
return c.uppercaseCharacter
default:
return c
}
}
Finally:
let s = map("Hello", flipCase)
// s is a String = "hELLO"
I hope this helps. inputString and resultString are the input and output respectively.
let inputString = "Example"
let outputString = inputString.characters.map { (character) -> Character in
let string = String(character)
let lower = string.lowercased()
let upper = string.uppercased()
return (string == lower) ? Character(upper) : Character(lower)
}
let resultString = String(outputString)
I have a list of string.
I want to get the list items that matches the other list.
i.e, if First List values contains the value from other string return all the values.
List<string> fileNameToMatch = new List<string> { "nsevar", "cat", "elm", "nse isin", "l6scripsv2eq" };
List<string> fileToMatch = new List<string> { "fevnsevarc", "gfcatgf","ratstts","mymatch"};
The second list contains the values the are present in first list.
So return all values.
The output should be "fevnsevarc" and "gfcatgf" in list.
Can we use some link to get the names from the fileToMatch which contain data from fileNameToMatch
This should do the trick:
var res = fileToMatch
.Where(f => fileNameToMatch.Any(fn => f.IndexOf(fn) >= 0))
.ToList();
This is nearly self-explanatory: you are looking for all files f in fileToMatch such that a file name fn exists in the fileNameToMatch where f is contained anywhere in fn as a substring.
EDIT : (in response to a comment) To get the fn along with f, add a Select, and use an anonymous type, like this:
var res = fileToMatch
.Where(f => fileNameToMatch.Any(fn => f.IndexOf(fn) >= 0))
.Select(f => new {
File = f
, Name = fileNameToMatch.First(fn => f.IndexOf(fn) >= 0)
})
.ToList();
foreach (var match in res) {
Console.WriteLine("{0} - {1}", match.File, match.Name);
}
This should work:
var result = fileToMatch.Where(x => fileNameToMatch.Any(y => x.Contains(y)));