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)
}

将Int转换为字符串:

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

而反过来-将String转换为Int:

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

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

如果你使用的是Swift 2或Swift 3:

let x: Int? = Int(myString)

为了完整起见，你还可以使用:

let x = 10.description

或支持描述的任何其他值。

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
            }
        }
    }
}

我更喜欢使用字符串插值

let x = 45
let string = "\(x)"

每个对象都有一些字符串表示。这样事情就简单多了。例如，如果您需要创建具有多个值的字符串。你也可以在里面做任何数学运算或者使用一些条件

let text = "\(count) \(count > 1 ? "items" : "item") in the cart. Sum: $\(sum + shippingPrice)"

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)"