Remove last character from string. Swift language

Question

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)

2017, MODERN ANSWER: stackoverflow.com/a/39610807/294884

Fattie
– Fattie

2017-01-18 00:13:21 +00:00
Commented Jan 18, 2017 at 0:13 — Fattie
– Fattie, Commented Jan 18, 2017 at 0:13

Craig Otis · Accepted Answer · 2019-05-07 13:46:49Z

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"

On Xcode 6 beta 6 :'String' doesn't have a member named substringToIndex
Hey, heads up, make sure it's substringToIndex not substringFromIndex. It doesn't make you feel intelligent mistaking this, let me tell you.
This is true, as of July 21st, Xcode 7 Beta 4 says 'String' doesn't have a member named substringToIndex. Also, as of Xcode 7, string no longer has a .count property, it is now only applied to characters: string.characters.count
Swift 3: var truncated = name.substring(to: name.index(before: name.endIndex))

Vitalii · Accepted Answer · 2016-04-30 14:04:45Z

91

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())

edited Apr 30, 2016 at 14:04

Vitalii

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answered Jul 24, 2014 at 11:28

gui_dos

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2 Comments

gui_dos Over a year ago

In Swift 2.0 the characters property on a String outputs a sequence, therefore now you have to use: expression = expression.characters.dropLast()

cromanelli Over a year ago

In Swift 2.0 for have to properly cast the result expression = String(expression.characters.dropLast()) if you want it back as a String

Carien van Zyl · Accepted Answer · 2017-09-28 09:08:57Z

74

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.

edited Sep 28, 2017 at 9:08

Carien van Zyl

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answered Aug 29, 2015 at 12:31

jrc

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1 Comment

Starsky Over a year ago

Could be just let choppedString = theString.dropLast().description.

Community · Accepted Answer · 2020-06-20 09:12:55Z

35

Swift 4/5

var str = "bla" str.removeLast() // returns "a"; str is now "bl"

edited Jun 20, 2020 at 9:12

CommunityBot

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answered Feb 12, 2019 at 1:28

idrougge

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Comments

Maxim Shoustin · Accepted Answer · 2015-04-19 23:05:58Z

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

Pang · Accepted Answer · 2015-04-01 03:33:13Z

6

Use the function removeAtIndex(i: String.Index) -> Character:

var s = "abc" s.removeAtIndex(s.endIndex.predecessor()) // "ab"

edited Apr 1, 2015 at 3:33

Pang

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answered Nov 14, 2014 at 12:17

Anton Serkov

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Comments

Carien van Zyl · Accepted Answer · 2017-09-26 13:53:22Z

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())

Kunal · Accepted Answer · 2016-07-31 11:17:32Z

5

The easiest way to trim the last character of the string is:

title = title[title.startIndex ..< title.endIndex.advancedBy(-1)]

answered Jul 31, 2016 at 11:17

Kunal

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1 Comment

Letaief Achraf Over a year ago

Thank you, a very elegant way to remove as many characters as you want from the end of a string.

Deepak Tagadiya · Accepted Answer · 2019-06-18 08:55:50Z

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

Channing · Accepted Answer · 2014-07-22 03:58:30Z

let str = "abc" let substr = str.substringToIndex(str.endIndex.predecessor()) // "ab"

Leo Dabus · Accepted Answer · 2015-04-01 03:31:29Z

2

var str = "Hello, playground" extension String { var stringByDeletingLastCharacter: String { return dropLast(self) } } println(str.stringByDeletingLastCharacter) // "Hello, playgroun"

answered Apr 1, 2015 at 3:31

Leo Dabus

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1 Comment

Leo Dabus Over a year ago

kkkk I didn't even remember of this one (Swift 1.2 above). for Swift 3 version stackoverflow.com/a/40028338/2303865

Jagat Dave · Accepted Answer · 2016-09-20 10:20:29Z

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.

Jorge Ramírez · Accepted Answer · 2017-09-20 09:00:30Z

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

Pang · Accepted Answer · 2015-04-01 03:32:43Z

Use the function advance(startIndex, endIndex):

var str = "45+22" str = str.substringToIndex(advance(str.startIndex, countElements(str) - 1))

Sunkas · Accepted Answer · 2015-05-20 10:01:05Z

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"

Kaiusee · Accepted Answer · 2016-10-27 19:14:43Z

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.

narco · Accepted Answer · 2016-11-20 15:50:13Z

Swift 3 (according to the docs) 20th Nov 2016

let range = expression.index(expression.endIndex, offsetBy: -numberOfCharactersToRemove)..<expression.endIndex expression.removeSubrange(range)

user7718859 · Accepted Answer · 2018-01-08 17:18:12Z

The dropLast() function removes the last element of the string.

var expression = "45+22" expression = expression.dropLast()

Ashfaqur_Rahman · Accepted Answer · 2018-12-06 02:51:28Z

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 }

n13 · Accepted Answer · 2015-08-04 11:14:02Z

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)

slashlos · Accepted Answer · 2018-10-21 15:11:26Z

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 } }

pkamb · Accepted Answer · 2019-11-23 06:30:37Z

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.

Nalam · Accepted Answer · 2022-08-12 19:55:45Z

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>

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