整数NEQ Int（整数）Craziness

我试图检测我是否已经乘以复数分数的分子和分母足够多的时间（到10/10），以获得整数在顶部和底部。通常我的算法有效。但有时候，Int()函数不能按预期工作，我从中得到大量数字。下面是我跑什么的简化版本：整数NEQ Int（整数）Craziness

<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>

这其中大部分的时间得到我想要的东西，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"

甚至是这样的：

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"

我在做什么错，我该如何弥补？

来源

2012-02-06 Dave Babbitt

-1

缬氨酸（）似乎纠正它太：

<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>

来源

2012-02-06 22:13:36 BKK

''解决问题并获得最少的循环时间。 – 2012-02-07 13:32:11

@Dave - 我对此有点怀疑;）PrecisionEvaluate通常会导致更少的迭代，因为它不使用像9.183999999这样的近似数字。因此，评估9.184需要四（4）次迭代，而不是~13（13）'val'。也就是说，除非您处理数百或数千个数字，否则这并不是一个显着的差异。 – Leigh 2012-02-07 17:58:27

尝试使用javacast .. ColdFusion试图动态确定您的变量类型，并且做得不好。Javacast涵盖了许多罪恶。

<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>

来源

2012-02-06 22:05:15

This：'“仍然获得巨大的数字。 – 2012-02-07 13:29:48

实数= “9.184E + 015”

输出是欺骗性的。如果您使用#RealNumber.toString()#，则实际值可能类似于9.183999999999998E15。 CF对大多数数学运算使用近似类型Double。所以你看到的是floating point numbers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）。

来源

2012-02-06 22:53:01 Leigh

'>仍然获得巨大的数字。 – 2012-02-07 13:31:08

这是因为你必须在两个值上使用它，例如'precisionEvaluate（RealNumber * 10）'。否则当你执行数学运算时，CF会回退到使用浮点数。 – Leigh 2012-02-07 17:36:30

整数NEQ Int（整数）Craziness

回答

相关问题