弦乐演奏

稍微讲讲性能 UI测试包在iPhone 7(真实设备)与iOS 14

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
            }
        }
    }
}

我正在使用这个简单的方法

字符串到Int:

 var a = Int()
var string1 = String("1")
a = string1.toInt()

和从Int到String:

var a = Int()
a = 1
var string1 = String()
 string1= "\(a)"

如果你喜欢快速扩展，你可以添加以下代码

extension Int
{
    var string:String {
        get {
            return String(self)
        }
    }
}

然后，您可以通过刚才添加的方法获取字符串

var x = 1234
var s = x.string

将Unicode Int转换为字符串

对于那些想要将Int转换为Unicode字符串的人，您可以执行以下操作:

let myInteger: Int = 97

// convert Int to a valid UnicodeScalar
guard let myUnicodeScalar = UnicodeScalar(myInteger) else {
    return ""
}

// convert UnicodeScalar to String
let myString = String(myUnicodeScalar)

// results
print(myString) // a

或者:

let myInteger: Int = 97
if let myUnicodeScalar = UnicodeScalar(myInteger) {
    let myString = String(myUnicodeScalar)
}

为了在将来节省你的时间和麻烦，你可以做一个Int扩展。通常我会创建一个共享代码文件，在其中放置扩展名、枚举和其他有趣的东西。下面是扩展代码的样子:

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

之后，当你想将int型转换为字符串时，你可以这样做:

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

在swift 3.0中，您可以将整数更改为字符串，如下所示

let a:String = String(stringInterpolationSegment: 15)

另一种方法是

let number: Int = 15
let _numberInStringFormate: String = String(number)

//或任何整数来代替15