整数 NEQ Int(Integer) 疯狂

Question

我试图检测是否已将复分数的分子和分母相乘足够多次（乘以 10/10）以获得顶部和底部的整数。我的算法通常有效。但有时，Int() 函数无法按预期工作，我会从中得到大量数据。这是我正在运行的简化版本：

<cfoutput>
    <cfset RealNumber = RandRange(1000, 10000) / 1000 />
    RealNumber = "#RealNumber#" Int(RealNumber) = "#Int(RealNumber)#"<br />
    <cfloop condition="RealNumber NEQ Int(RealNumber)">
        <cfset RealNumber = RealNumber * 10 />
        RealNumber = "#RealNumber#" Int(RealNumber) = "#Int(RealNumber)#"<br />
    </cfloop>
</cfoutput>

大多数时候这会得到我想要的，但有时它看起来像这样：

RealNumber = "9.184" Int(RealNumber) = "9"
RealNumber = "91.84" Int(RealNumber) = "91"
RealNumber = "918.4" Int(RealNumber) = "918"
RealNumber = "9184" Int(RealNumber) = "9183"
RealNumber = "91840" Int(RealNumber) = "91839"
RealNumber = "918400" Int(RealNumber) = "918399"
RealNumber = "9184000" Int(RealNumber) = "9183999"
RealNumber = "91840000" Int(RealNumber) = "91839999"
RealNumber = "918400000" Int(RealNumber) = "918399999"
RealNumber = "9184000000" Int(RealNumber) = "9183999999"
RealNumber = "91840000000" Int(RealNumber) = "91839999999"
RealNumber = "918400000000" Int(RealNumber) = "918399999999"
RealNumber = "9.184E+012" Int(RealNumber) = "9.184E+012"
RealNumber = "9.184E+013" Int(RealNumber) = "9.184E+013"
RealNumber = "9.184E+014" Int(RealNumber) = "9.184E+014"
RealNumber = "9.184E+015" Int(RealNumber) = "9.184E+015"

或者甚至像这样：

RealNumber = "2.152" Int(RealNumber) = "2"
RealNumber = "21.52" Int(RealNumber) = "21"
RealNumber = "215.2" Int(RealNumber) = "215"
RealNumber = "2152" Int(RealNumber) = "2152"
RealNumber = "21520" Int(RealNumber) = "21520"
RealNumber = "215200" Int(RealNumber) = "215200"
RealNumber = "2152000" Int(RealNumber) = "2152000"
RealNumber = "21520000" Int(RealNumber) = "21520000"
RealNumber = "215200000" Int(RealNumber) = "215200000"
RealNumber = "2152000000" Int(RealNumber) = "2152000000"
RealNumber = "21520000000" Int(RealNumber) = "21520000000"
RealNumber = "215200000000" Int(RealNumber) = "215200000000"
RealNumber = "2.152E+012" Int(RealNumber) = "2.152E+012"
RealNumber = "2.152E+013" Int(RealNumber) = "2.152E+013"
RealNumber = "2.152E+014" Int(RealNumber) = "2.152E+014"
RealNumber = "2.152E+015" Int(RealNumber) = "2.152E+015"
RealNumber = "2.152E+016" Int(RealNumber) = "2.152E+016"

我做错了什么以及如何弥补？

Answer 1

实数 = "9.184E+015"

输出具有欺骗性。如果您使用#RealNumber.toString()#，实际值可能类似于9.183999999999998E15。 CF 对于大多数情况使用近似类型 Double数学运算。因此，您所看到的是浮点数的正常行为。如果您需要更高的准确度，请使用 PrecisionEvaluate。它使用 BigDecimals 进行算术运算（因为它们比 java.lang.Double 更精确）。

Answer 2

尝试使用 javacast.. ColdFusion 正在尝试动态确定您的变量类型，但做得并不好.. Javacast 涵盖了许多错误。

<cfoutput>
<cfset RealNumber = RandRange(1000, 10000) / 1000 />
RealNumber = "#RealNumber#" Int(RealNumber) = "#Int(RealNumber)#"<br />
<cfloop condition="RealNumber NEQ Int(RealNumber)">
    <cfset RealNumber = RealNumber * 10 />
    RealNumber = "#RealNumber#" Int(RealNumber) = "#javaCast("int", RealNumber)#"<br />
</cfloop>

Answer 3

Val() 似乎也纠正了它：

<cfoutput>

    <cfset RealNumber = RandRange(1000, 10000) / 1000 />
    "#val(RealNumber)#" = INT: "#val(Int(RealNumber))#"<br />
    <cfloop condition="val(RealNumber) NEQ Val(Int(RealNumber))">
        <cfset RealNumber = RealNumber * 10 />
        "#val(RealNumber)#" INT: "#val(Int(RealNumber))#"<br />
    </cfloop>

</cfoutput>