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。

斯威夫特4:

试图在label中显示没有Optional()字的值。

这里x是一个Int值使用。

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

斯威夫特2:

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

不管出于什么原因，这个公认的答案对我不起作用。我采用了这样的方法:

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

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)

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
            }
        }
    }
}