在Swift中从String转换为Decimal时，decimal值会被删除 [英] Decimal values get remove when convert from String to Decimal in Swift

问题描述

请检查此示例

 let strValue = "12.00"
 let decimalValue = Decimal(string: strValue) // 12

它总是返回12而不是12.00 我也尝试使用NSNumber，Float和Double，但是它总是删除零.

it always returns 12 not 12.00 I also try with NSNumber, Float, and Double but it always remove zeros.

您能先谢谢我吗?

推荐答案

就像马丁说的那样. 12和12.00是相同的数字.逗号后面有多少个0并不重要.

Like martin said. 12 and 12.00 is the same number. It doesn't mathematical matter how many 0 are behind the comma.

虽然数字保持不变，但表示形式却是不同的主题.

While a number stays the same, the representation is a different topic.

字符串(格式:％.6f"，12)将给出12.000000作为字符串.

String(format: "%.6f", 12) will give 12.000000 as String.

小数是结构.数字的含义保持不变.扔到操场上.

A Decimal is a Struct. The meaning of the numbers stays the same. Throw this in a playground.

import UIKit
let decimal = Decimal(12.0000000000)
let justAnInt = 12

let sameDecimal = decimal == Decimal(justAnInt)

看到了吗?数学中没有无限0这样的东西.零是有限的.从12000000开始的小数和从12开始创建的小数是相同的.

See? There is no such thing as infinite 0 in math. Zero is finite. A Decimal from 12.000000 and a Decimal created from 12 are the same.

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