I would like to generate a list of words form a given string where each listed word contains at least an upper case letter.
Having a string like this one:
let str: String = "Apple watchOS 3 USA release date and feature rumours."
I would like to get an array like this:
var list: [String] = ["Apple", "watchOS", "USA"]
What is the best way to do this?
var list = str.componentsSeparatedByString(" ").filter{ $0.lowercaseString != $0 }
You can use built in function of String in Swift that get all words of a string. It's better than just separate by a space (" ") cause you can have some words with a point (like the example below)
let str = "Apple watchOS 3 USA release date and feature Rumours."
var list = [String]()
str.enumerateSubstringsInRange(str.startIndex..<str.endIndex, options:.ByWords) {
(substring, substringRange, enclosingRange, value) in
//add to your array if lowercase != string original
if let _subString = substring where _subString.lowercaseString != _subString {
list.append(_subString)
}
}
You can probably do something like this. I haven't tested it, just wrote it real quick.
let str = "Apple watchOS 3 USA release date and feature rumours."
let strArr = str.componentsSeparatedByString(" ")
var upperWords: Array<String> = []
for word in strArr {
if word != word.lowercaseString {
upperWords.append(word)
}
}
How can I remove last character from String variable using Swift? Can't find it in documentation.
Here is full example:
var expression = "45+22"
expression = expression.substringToIndex(countElements(expression) - 1)
Swift 4.0 (also Swift 5.0)
var str = "Hello, World" // "Hello, World"
str.dropLast() // "Hello, Worl" (non-modifying)
str // "Hello, World"
String(str.dropLast()) // "Hello, Worl"
str.remove(at: str.index(before: str.endIndex)) // "d"
str // "Hello, Worl" (modifying)
Swift 3.0
The APIs have gotten a bit more swifty, and as a result the Foundation extension has changed a bit:
var name: String = "Dolphin"
var truncated = name.substring(to: name.index(before: name.endIndex))
print(name) // "Dolphin"
print(truncated) // "Dolphi"
Or the in-place version:
var name: String = "Dolphin"
name.remove(at: name.index(before: name.endIndex))
print(name) // "Dolphi"
Thanks Zmey, Rob Allen!
Swift 2.0+ Way
There are a few ways to accomplish this:
Via the Foundation extension, despite not being part of the Swift library:
var name: String = "Dolphin"
var truncated = name.substringToIndex(name.endIndex.predecessor())
print(name) // "Dolphin"
print(truncated) // "Dolphi"
Using the removeRange() method (which alters the name):
var name: String = "Dolphin"
name.removeAtIndex(name.endIndex.predecessor())
print(name) // "Dolphi"
Using the dropLast() function:
var name: String = "Dolphin"
var truncated = String(name.characters.dropLast())
print(name) // "Dolphin"
print(truncated) // "Dolphi"
Old String.Index (Xcode 6 Beta 4 +) Way
Since String types in Swift aim to provide excellent UTF-8 support, you can no longer access character indexes/ranges/substrings using Int types. Instead, you use String.Index:
let name: String = "Dolphin"
let stringLength = count(name) // Since swift1.2 `countElements` became `count`
let substringIndex = stringLength - 1
name.substringToIndex(advance(name.startIndex, substringIndex)) // "Dolphi"
Alternatively (for a more practical, but less educational example) you can use endIndex:
let name: String = "Dolphin"
name.substringToIndex(name.endIndex.predecessor()) // "Dolphi"
Note: I found this to be a great starting point for understanding String.Index
Old (pre-Beta 4) Way
You can simply use the substringToIndex() function, providing it one less than the length of the String:
let name: String = "Dolphin"
name.substringToIndex(countElements(name) - 1) // "Dolphi"
The global dropLast() function works on sequences and therefore on Strings:
var expression = "45+22"
expression = dropLast(expression) // "45+2"
// in Swift 2.0 (according to cromanelli's comment below)
expression = String(expression.characters.dropLast())
Swift 4:
let choppedString = String(theString.dropLast())
In Swift 2, do this:
let choppedString = String(theString.characters.dropLast())
I recommend this link to get an understanding of Swift strings.
Swift 4/5
var str = "bla"
str.removeLast() // returns "a"; str is now "bl"
This is a String Extension Form:
extension String {
func removeCharsFromEnd(count_:Int) -> String {
let stringLength = count(self)
let substringIndex = (stringLength < count_) ? 0 : stringLength - count_
return self.substringToIndex(advance(self.startIndex, substringIndex))
}
}
for versions of Swift earlier than 1.2:
...
let stringLength = countElements(self)
...
Usage:
var str_1 = "Maxim"
println("output: \(str_1.removeCharsFromEnd(1))") // "Maxi"
println("output: \(str_1.removeCharsFromEnd(3))") // "Ma"
println("output: \(str_1.removeCharsFromEnd(8))") // ""
Reference:
Extensions add new functionality to an existing class, structure, or enumeration type. This includes the ability to extend types for which you do not have access to the original source code (known as retroactive modeling). Extensions are similar to categories in Objective-C. (Unlike Objective-C categories, Swift extensions do not have names.)
See DOCS
Use the function removeAtIndex(i: String.Index) -> Character:
var s = "abc"
s.removeAtIndex(s.endIndex.predecessor()) // "ab"
Swift 4
var welcome = "Hello World!"
welcome = String(welcome[..<welcome.index(before:welcome.endIndex)])
or
welcome.remove(at: welcome.index(before: welcome.endIndex))
or
welcome = String(welcome.dropLast())
The easiest way to trim the last character of the string is:
title = title[title.startIndex ..< title.endIndex.advancedBy(-1)]
import UIKit
var str1 = "Hello, playground"
str1.removeLast()
print(str1)
var str2 = "Hello, playground"
str2.removeLast(3)
print(str2)
var str3 = "Hello, playground"
str3.removeFirst(2)
print(str3)
Output:-
Hello, playgroun
Hello, playgro
llo, playground
let str = "abc"
let substr = str.substringToIndex(str.endIndex.predecessor()) // "ab"
var str = "Hello, playground"
extension String {
var stringByDeletingLastCharacter: String {
return dropLast(self)
}
}
println(str.stringByDeletingLastCharacter) // "Hello, playgroun"
Short answer (valid as of 2015-04-16): removeAtIndex(myString.endIndex.predecessor())
Example:
var howToBeHappy = "Practice compassion, attention and gratitude. And smile!!"
howToBeHappy.removeAtIndex(howToBeHappy.endIndex.predecessor())
println(howToBeHappy)
// "Practice compassion, attention and gratitude. And smile!"
Meta:
The language continues its rapid evolution, making the half-life for many formerly-good S.O. answers dangerously brief. It's always best to learn the language and refer to real documentation.
With the new Substring type usage:
Swift 4:
var before: String = "Hello world!"
var lastCharIndex: Int = before.endIndex
var after:String = String(before[..<lastCharIndex])
print(after) // Hello world
Shorter way:
var before: String = "Hello world!"
after = String(before[..<before.endIndex])
print(after) // Hello world
Use the function advance(startIndex, endIndex):
var str = "45+22"
str = str.substringToIndex(advance(str.startIndex, countElements(str) - 1))
A swift category that's mutating:
extension String {
mutating func removeCharsFromEnd(removeCount:Int)
{
let stringLength = count(self)
let substringIndex = max(0, stringLength - removeCount)
self = self.substringToIndex(advance(self.startIndex, substringIndex))
}
}
Use:
var myString = "abcd"
myString.removeCharsFromEnd(2)
println(myString) // "ab"
Another way If you want to remove one or more than one character from the end.
var myStr = "Hello World!"
myStr = (myStr as NSString).substringToIndex((myStr as NSString).length-XX)
Where XX is the number of characters you want to remove.
Swift 3 (according to the docs) 20th Nov 2016
let range = expression.index(expression.endIndex, offsetBy: -numberOfCharactersToRemove)..<expression.endIndex
expression.removeSubrange(range)
The dropLast() function removes the last element of the string.
var expression = "45+22"
expression = expression.dropLast()
Swift 4.2
I also delete my last character from String (i.e. UILabel text) in IOS app
#IBOutlet weak var labelText: UILabel! // Do Connection with UILabel
#IBAction func whenXButtonPress(_ sender: UIButton) { // Do Connection With X Button
labelText.text = String((labelText.text?.dropLast())!) // Delete the last caracter and assign it
}
I'd recommend using NSString for strings that you want to manipulate. Actually come to think of it as a developer I've never run into a problem with NSString that Swift String would solve... I understand the subtleties. But I've yet to have an actual need for them.
var foo = someSwiftString as NSString
or
var foo = "Foo" as NSString
or
var foo: NSString = "blah"
And then the whole world of simple NSString string operations is open to you.
As answer to the question
// check bounds before you do this, e.g. foo.length > 0
// Note shortFoo is of type NSString
var shortFoo = foo.substringToIndex(foo.length-1)
Swift 3: When you want to remove trailing string:
func replaceSuffix(_ suffix: String, replacement: String) -> String {
if hasSuffix(suffix) {
let sufsize = suffix.count < count ? -suffix.count : 0
let toIndex = index(endIndex, offsetBy: sufsize)
return substring(to: toIndex) + replacement
}
else
{
return self
}
}
complimentary to the above code I wanted to remove the beginning of the string and could not find a reference anywhere. Here is how I did it:
var mac = peripheral.identifier.description
let range = mac.startIndex..<mac.endIndex.advancedBy(-50)
mac.removeRange(range) // trim 17 characters from the beginning
let txPower = peripheral.advertisements.txPower?.description
This trims 17 characters from the beginning of the string (he total string length is 67 we advance -50 from the end and there you have it.
I prefer the below implementation because I don't have to worry even if the string is empty
let str = "abc"
str.popLast()
// Prints ab
str = ""
str.popLast() // It returns the Character? which is an optional
// Print <emptystring>
How can I define a Dictionary with string key in AS3? and how to do read operation?
for example:
var Dic:Dictionary = new Dictionary();
Dic["Exhausted"] = "He who talks more is sooner exhausted, please keep smiling :)";
String str = str.substring(8,str.length-1); // == str = "Exhausted";
trace('Dic[' + str + '] = ' + Dic[str]);
the output is Dic[Exhausted] = undefined???!!
why?
I think you have a syntax error on this line:
String str = str.substring(8,str.length-1);
If you just use this :
var d:Dictionary = new Dictionary();
d["Exhausted"] = "He who talks more is sooner exhausted, please keep smiling :)";
trace(d["Exhausted"]);
You can see it's all fine.
The problem with var str:String = str.substring(8,str.length-1); is that you define a String named "str": var str:String, but you assign a value which is the result of the substring() method called on str and of cours str does not exist yet when you call substring on it.
Not sure if this makes sense: you define str as the result of applying substring on str.
The actionscript compiler should've complained btw:
expected a definition keyword (such as function) after attribute String, not str.
Just a wild guess, but would you happen to have str defined somewhere else in your code and you just update str again using str before using it ? In which case, you shouldn't redefine, str, you should simply assign a new value.
e.g.
//somewhere else
var str:String = "12345678Exhausted";
//further down
var Dic:Dictionary = new Dictionary();
Dic["Exhausted"] = "He who talks more is sooner exhausted, please keep smiling :)";
str = str.substring(8,str.length); // == str = "Exhausted";
trace('Dic[' + str + '] = ' + Dic[str]);
Also, another syntax error is how you define str:
should be var str:String (as2/as3 syntax), not String str(java/c++/etc. style)
ArrayList arr = new ArrayList();
string abc =
What should I do to convert arraylist to a string such as abc = arr;Updated QuestOther consideration from which i can complete my work is concatination of string(need help in that manner ). suppose i have a string s="abcdefghi.."by applying foreach loop on it and getting char by matching some condition and concatinating every char value in some insatnce variable of string type i.e string subString=+;Something like thisstring tem = string.Empty;
string temp =string.Empty;
temp = string.Concat(tem,temp);
Using a little linq and making the assumption that your ArrayList contains string types:
using System.Linq;
var strings = new ArrayList().Cast<string>().ToArray();
var theString = string.Join(" ", strings);
Further reading:
http://msdn.microsoft.com/en-us/library/57a79xd0.aspx
For converting other types to string:
var strings = from object o in myArrayList
select o.ToString();
var theString = string.Join(" ", strings.ToArray());
The first argument to the Join method is the separator, I chose whitespace. It sounds like your chars should all contribute without a separator, so use "" or string.Empty instead.
Update: if you want to concatenate a small number of strings, the += operator will suffice:
var myString = "a";
myString += "b"; // Will equal "ab";
However, if you are planning on concatenating an indeterminate number of strings in a tight loop, use the StringBuilder:
using System.Text;
var sb = new StringBuilder();
for (int i = 0; i < 10; i++)
{
sb.Append("a");
}
var myString = sb.ToString();
This avoids the cost of lots of string creations due to the immutability of strings.
Look into string.Join(), the opposite of string.Split()
You'll also need to convert your arr to string[], I guess that ToArray() will help you do that.
Personally and for memory preservation I’ll do for a concatenation:
System.Collections.ArrayList Collect = new System.Collections.ArrayList();
string temporary = string.Empty;
Collect.Add("Entry1");
Collect.Add("Entry2");
Collect.Add("Entry3");
foreach (String var in Collect)
{
temporary = temporary + var.ToString();
}
textBox1.Text = temporary;
What would be the best way to simply take a string like
var myString:String = "Thi$ i$ a T#%%Ible Exam73#";
and make myString = "thiiatibleeam";
or another example
var myString:String = "Totally Awesome String";
and make myString = "totallyawesomestring";
In actionscript 3 Thanks!
Extending #Sam OverMars' answer, you can use a combination of String's replace method with a Regex and String's toLowerCase method to get what you're looking for.
var str:String = "Thi$ i$ a T#%%Ible Exam73#";
str = str.toLowerCase(); //thi$ i$ a t#%%ible exam73#
str = str.replace(/[^a-z]/g,""); //thiiatibleexam
The regular expression means:
[^a-z] -- any character *not* in the range a-z
/g -- global tag means find all, not just find one
I think this is the regex you're looking for:
[Bindable]
var myString:String = "Thi$ i$ a T#%%Ible Exam73#";
[Bindable]
var anotherString:String = "";
protected function someFunction():void
{
anotherString = myString.replace(/[^a-zA-Z]/g, "");
anotherString = anotherString.toLowerCase();
}
I belive what your looking for is:
var myString = str.replace("find", "replace");
or in your case:
str.replace("$", "");
also, it might be:
str.replace('$', ' ');
//EDIT
How about:
var mySearch:RegExp = /(\t|\n|\s{1,})/g;
var myString = str.replace(mySearch, "");