在Swift中将Int转换为String

Question

我正试图找出如何在Swift中Int投入一个String.

我想出了一个解决方法,使用NSNumber但我想知道如何在Swift中完成所有操作.

let x : Int = 45
let xNSNumber = x as NSNumber
let xString : String = xNSNumber.stringValue

Answer 1

转换Int为String:

let x : Int = 42
var myString = String(x)

反过来 - 转换String为Int:

let myString : String = "42"
let x: Int? = myString.toInt()

if (x != nil) {
    // Successfully converted String to Int
}

或者,如果您使用的是Swift 2或3:

let x: Int? = Int(myString)

Answer 2

检查下面的答案:

let x : Int = 45
var stringValue = "\(x)"
print(stringValue)

Answer 3

这里有4种方法:

var x = 34
var s = String(x)
var ss = "\(x)"
var sss = toString(x)
var ssss = x.description

我可以想象有些人会遇到ss的问题.但是如果你想构建一个包含其他内容的字符串,那么为什么不呢.

Answer 4

在Swift 3.0中:

var value: Int = 10
var string = String(describing: value)

Answer 5

斯威夫特4:

let x:Int = 45
let str:String = String(describing: x)

Developer.Apple.com> String> init(描述:)

String(描述:)初始化程序是将任何类型的实例转换为字符串的首选方法.

developer.apple.com

Answer 6

为了完整起见,您还可以使用:

let x = 10.description

或任何其他支持描述的值.

Answer 7

斯威夫特4:

尝试在没有Optional()字的情况下显示标签中的值.

这里x是使用的Int值.

let str:String = String(x ?? 0)

Answer 8

为了节省您自己的时间和麻烦,您可以进行Int扩展.通常我会创建一个共享代码文件,我在其中放置扩展,枚举和其他有趣的东西.这是扩展代码的样子:

extension Int
{
    func toString() -> String
    {
        var myString = String(self)
        return myString
    }
}

然后,当您想要将int转换为字符串时,您可以执行以下操作:

var myNumber = 0
var myNumberAsString = myNumber.toString()

Answer 9

无论出于何种原因,接受的答案对我都不起作用.我采用这种方法:

var myInt:Int = 10
var myString:String = toString(myInt)

Answer 10

在SWIFT 3.0,这是我们如何能够转换Int到String和String到Int

//convert Integer to String in Swift 3.0

let theIntegerValue :Int = 123  // this can be var also
let theStringValue :String = String(theIntegerValue)


//convert String to Integere in Swift 3.0


let stringValue : String = "123"
let integerValue : Int = Int(stringValue)!

Answer 11

let intAsString = 45.description     // "45"
let stringAsInt = Int("45")          // 45

Answer 12

Swift 字符串性能

UI Testing Bundle关于运行 iOS 14 的 iPhone 7（真实设备）上的性能的一些信息

let i = 0
lt result1 = String(i) //0.56s 5890kB
lt result2 = "\(i)" //0.624s 5900kB
lt result3 = i.description //0.758s 5890kB

import XCTest

class ConvertIntToStringTests: XCTestCase {
    let count = 1_000_000
    
    func measureFunction(_ block: () -> Void) {
        let metrics: [XCTMetric] = [
            XCTClockMetric(),
            XCTMemoryMetric()
        ]
        let measureOptions = XCTMeasureOptions.default
        measureOptions.iterationCount = 5
        
        measure(metrics: metrics, options: measureOptions) {
            block()
        }
    }

    func testIntToStringConstructor() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += String(i)
            }
        }
    }
    
    func testIntToStringInterpolation() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += "\(i)"
            }
        }
    }
    
    func testIntToStringDescription() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += i.description
            }
        }
    }
}

Answer 13

多种方法:

var str1:String="\(23)"
var str2:String=String(format:"%d",234)

Answer 14

斯威夫特2：

var num1 = 4
var numString = "56"
var sum2 = String(num1) + numString
var sum3 = Int(numString)