swift - 获取字符串的长度(Get the length of a String)

Question

How do you get the length of a String ?

(你如何得到一个String的长度？)

For example, I have a variable defined like:

(例如，我有一个定义如下的变量：)

var test1: String = "Scott"

However, I can't seem to find a length method on the string.

(但是，我似乎无法在字符串上找到长度方法。)

  ask by Scott Walter translate from so

Answer 1

Swift 5+:

(迅捷5+：)

test1.count

(Swift 5.0 strings can, in some ways, simply be treated as an array. Hence you can use .count or for example .first )

(（在某些方面，Swift 5.0字符串可以简单地视为一个数组。因此，您可以使用.count或例如.first ）)

---

As of Swift 4

(从Swift 4开始)

It's just:

(只是：)

test1.count

for reasons.

(原因。)

(Thanks to Martin R)

(（感谢Martin R）)

As of Swift 2:

(从Swift 2开始：)

With Swift 2, Apple has changed global functions to protocol extensions, extensions that match any type conforming to a protocol.

(在Swift 2中，Apple已将全局功能更改为协议扩展，这些扩展可与符合协议的任何类型匹配。)

Thus the new syntax is:

(因此，新语法为：)

test1.characters.count

(Thanks to JohnDifool for the heads up)

(（感谢JohnDifool的注意）)

As of Swift 1

(从Swift 1开始)

Use the count characters method:

(使用计数字符方法：)

let unusualMenagerie = "Koala 🐨, Snail 🐌, Penguin 🐧, Dromedary 🐪"
println("unusualMenagerie has (count(unusualMenagerie)) characters")
// prints "unusualMenagerie has 40 characters"

right from the Apple Swift Guide

(直接来自Apple Swift指南)

(note, for versions of Swift earlier than 1.2, this would be countElements(unusualMenagerie) instead)

(（请注意，对于早于1.2的Swift版本，它将countElements(unusualMenagerie) ）)

for your variable, it would be

(对于您的变量，它将是)

length = count(test1) // was countElements in earlier versions of Swift

Or you can use test1.utf16count

(或者您可以使用test1.utf16count)