blocks|key|92529|text|运行2%7C4的结果为TRUE。这就是为什么在比较1+==+TRUE时会获得TRUE。您想要评估的是(1+==+2)+%7C+(1+==+4)，它会产生所需的FALSE。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|92530|entityMap^0|2|3|9|4|N|9|10|4|1C|J|23|5|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|G|$]]

Running <code>2|4</code> evaluates to <code>TRUE</code>. That is why you obtain <code>TRUE</code> when comparing <code>1 == TRUE</code>. What you want to evaluate is <code>(1 == 2) | (1 == 4)</code>, which results in the desired <code>FALSE</code>.

blocks|key|92543|text|1+==+2+%7C+4|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|92544|Operator+precedence告诉我们它等同于(1+==+2)+%7C+4|unstyled|offset|length|style|CODE|92545|1+==+2是FALSE，4被强制为逻辑(因为%7C是一个逻辑运算符)，as.logical(4)是TRUE，所以你有FALSE+%7C+TRUE，那就是TRUE|92546|事实上，coercion+rules+for+logical+operators+(?Logic)告诉我们：|92547|92548|数值和复数向量将被强制为逻辑值，其中零为假，所有非零值为真。|blockquote|92549|92550|92551|92552|3+==+2+%7C+4|92553|同样的事情|92554|92555|1+==+(2+%7C+4)|92556|2+%7C+4将被强制为TRUE+%7C+TRUE，即TRUE。然后，1+==+TRUE被强制为1+==+1，即TRUE。|92557|事实上，coercion+rules+for+comparison+operators+(?Comparison)告诉我们：|92558|92559|如果两个参数是不同类型的原子向量，则一个参数被强制转换为另一个参数的类型，优先级(降序)为字符、复杂、数字、整数、逻辑和raw。|92560|92561|92562|92563|as.numeric(1)+==+(2+%7C+4)|92564|92565|92566|1L+==+(2+%7C+4)|92567|又是一样的|92568|92569|1等于2或4|BOLD|92570|实际上是(1等于2)或(1等于4)，即：|92571|(1==2)%7C(1==4)|92572|这就是|92573|FALSE+%7C+FALSE|92574|哪一个是FALSE|92575|entityMap|0|LINK|mutability|MUTABLE|url|https://stat.ethz.ch/R-manual/R-devel/library/base/html/Syntax.html|1|http://stat.ethz.ch/R-manual/R-devel/library/base/html/Logic.html|2|https://stat.ethz.ch/R-manual/R-devel/library/base/html/Comparison.html^0|0|R|C|0|J|0|0|0|6|7|5|N|1|Y|D|1C|4|1L|C|21|4|0|16|6|4|10|1|0|0|0|0|0|0|0|0|0|0|0|5|A|B|N|4|V|9|18|6|1G|4|0|19|B|4|13|2|0|0|0|0|0|0|0|0|0|0|0|0|0|6|0|0|0|0|0|4|5|0^^$0|@$1|2|3|4|5|6|7|2A|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|2B|8|@$G|2C|H|2D|I|J]]|9|@$G|2E|H|2F|1|2G]]|A|$]]|$1|K|3|L|5|F|7|2H|8|@$G|2I|H|2J|I|J]|$G|2K|H|2L|I|J]|$G|2M|H|2N|I|J]|$G|2O|H|2P|I|J]|$G|2Q|H|2R|I|J]|$G|2S|H|2T|I|J]|$G|2U|H|2V|I|J]]|9|@]|A|$]]|$1|M|3|N|5|F|7|2W|8|@$G|2X|H|2Y|I|J]]|9|@$G|2Z|H|30|1|31]]|A|$]]|$1|O|3|-4|5|F|7|32|8|@]|9|@]|A|$]]|$1|P|3|Q|5|R|7|33|8|@]|9|@]|A|$]]|$1|S|3|-4|5|F|7|34|8|@]|9|@]|A|$]]|$1|T|3|-4|5|F|7|35|8|@]|9|@]|A|$]]|$1|U|3|-4|5|F|7|36|8|@]|9|@]|A|$]]|$1|V|3|W|5|6|7|37|8|@]|9|@]|A|$B|C]]|$1|X|3|Y|5|F|7|38|8|@]|9|@]|A|$]]|$1|Z|3|-4|5|F|7|39|8|@]|9|@]|A|$]]|$1|10|3|11|5|6|7|3A|8|@]|9|@]|A|$B|C]]|$1|12|3|13|5|F|7|3B|8|@$G|3C|H|3D|I|J]|$G|3E|H|3F|I|J]|$G|3G|H|3H|I|J]|$G|3I|H|3J|I|J]|$G|3K|H|3L|I|J]|$G|3M|H|3N|I|J]]|9|@]|A|$]]|$1|14|3|15|5|F|7|3O|8|@$G|3P|H|3Q|I|J]]|9|@$G|3R|H|3S|1|3T]]|A|$]]|$1|16|3|-4|5|F|7|3U|8|@]|9|@]|A|$]]|$1|17|3|18|5|R|7|3V|8|@]|9|@]|A|$]]|$1|19|3|-4|5|F|7|3W|8|@]|9|@]|A|$]]|$1|1A|3|-4|5|F|7|3X|8|@]|9|@]|A|$]]|$1|1B|3|-4|5|F|7|3Y|8|@]|9|@]|A|$]]|$1|1C|3|1D|5|6|7|3Z|8|@]|9|@]|A|$B|C]]|$1|1E|3|Y|5|F|7|40|8|@]|9|@]|A|$]]|$1|1F|3|-4|5|F|7|41|8|@]|9|@]|A|$]]|$1|1G|3|1H|5|6|7|42|8|@]|9|@]|A|$B|C]]|$1|1I|3|1J|5|F|7|43|8|@]|9|@]|A|$]]|$1|1K|3|-4|5|F|7|44|8|@]|9|@]|A|$]]|$1|1L|3|1M|5|F|7|45|8|@$G|46|H|47|I|1N]]|9|@]|A|$]]|$1|1O|3|1P|5|F|7|48|8|@]|9|@]|A|$]]|$1|1Q|3|1R|5|6|7|49|8|@]|9|@]|A|$B|C]]|$1|1S|3|1T|5|F|7|4A|8|@]|9|@]|A|$]]|$1|1U|3|1V|5|6|7|4B|8|@]|9|@]|A|$B|C]]|$1|1W|3|1X|5|F|7|4C|8|@$G|4D|H|4E|I|J]]|9|@]|A|$]]|$1|1Y|3|-4|5|F|7|4F|8|@]|9|@]|A|$]]]|1Z|$20|$5|21|22|23|A|$24|25]]|26|$5|21|22|23|A|$24|27]]|28|$5|21|22|23|A|$24|29]]]]

<pre><code>1 == 2 | 4
</code></pre>

<a href="https://stat.ethz.ch/R-manual/R-devel/library/base/html/Syntax.html" rel="nofollow noreferrer">Operator precedence</a> tells us it is equivalent to <code>(1 == 2) | 4</code>

<code>1 == 2</code> is <code>FALSE</code>, 4 is coerced to logical (because <code>|</code>is a logical operator), <code>as.logical(4)</code> is <code>TRUE</code>, so you have <code>FALSE | TRUE</code>, that's <code>TRUE</code>

Indeed <a href="http://stat.ethz.ch/R-manual/R-devel/library/base/html/Logic.html" rel="nofollow noreferrer">coercion rules for logical operators</a> (<code>?Logic</code>) tell us that:

<blockquote>
 Numeric and complex vectors will be coerced to logical values, with
 zero being false and all non-zero values being true.
</blockquote>

<hr>

<pre><code>3 == 2 | 4
</code></pre>

Same thing

<hr>

<pre><code>1 == (2 | 4)
</code></pre>

<code>2 | 4</code> will be coerced to <code>TRUE | TRUE</code>, which is <code>TRUE</code>. Then <code>1 == TRUE</code> is coerced to <code>1 == 1</code> which is <code>TRUE</code>.

Indeed <a href="https://stat.ethz.ch/R-manual/R-devel/library/base/html/Comparison.html" rel="nofollow noreferrer">coercion rules for comparison operators</a> (<code>?Comparison</code>) tell us that:

<blockquote>
 If the two arguments are atomic vectors of different types, one is
 coerced to the type of the other, the (decreasing) order of precedence
 being character, complex, numeric, integer, logical and raw.
</blockquote>

<hr>

<pre><code>as.numeric(1) == (2 | 4)
</code></pre>

Same thing

<hr>

<pre><code>1L == (2 | 4)
</code></pre>

Same again

<hr>

1 is equal to 2 or 4

is actually (1 is equal to 2) or (1 is equal to 4), which is:

<pre><code>(1==2)|(1==4)
</code></pre>

which is

<pre><code>FALSE | FALSE
</code></pre>

which is <code>FALSE</code>

blocks|key|92450|text|为你的第一句话中隐含的问题提供预期答案的代码是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|92451|1+%25in%25+2:4
[1]+FALSE

h=1
h+%25in%25+1:2
[1]+TRUE|code-block|syntax|javascript|92452|"==“运算符不会从逻辑合取中隐式生成范围(或备选方案的向量)。它被认为是一种“比较”-operator，是“泛型”的，这意味着对于不同的数据类型，方法可以是不同的。它们也是矢量化的(使用有效的隐式回收规则)，因此可能会返回许多值：|92453|(1:2)+==+(1:4)
[1]++TRUE++TRUE+FALSE+FALSE|92454|并且应用于值1的as.numeric()-function将精确地返回输入。|offset|length|style|CODE|92455|进一步说明:由于您尝试使用的"==“实际上是一个隐式的设置操作，因此您可能需要查看?intersect的帮助页面。还有一些包可以处理更复杂的set函数。|92456|R的强制可以在逻辑和数字之间来回切换，这取决于函数的定义方式：|92457|sum(+letters[1:10]+%25in%25+letters)
[1]+10

sum(+letters[1:10]+==+letters)
[1]+10
Warning+message:
In+letters[1:10]+==+letters+:
++longer+object+length+is+not+a+multiple+of+shorter+object+length|92458|entityMap^0|0|0|0|0|6|1|8|C|0|15|A|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|12|8|@$M|13|N|14|O|P]|$M|15|N|16|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|6|7|17|8|@$M|18|N|19|O|P]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1A|8|@]|9|@]|A|$]]|$1|U|3|V|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|W|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|X|$]]

The code that will deliver the expected answer to the implicit question in your first sentence is:

<pre><code>1 %in% 2:4
[1] FALSE

h=1
h %in% 1:2
[1] TRUE
</code></pre>

The "==" operator does not implicitly generate a range (or a vector of alternatives) from a logical conjunction. It is considered a "Comparison"-operator and is "generic" which will mean that methods can be different for different data-types. They are also vectorized (with the implicit recycling rules in force) so may return many values:

<pre><code>(1:2) == (1:4)
[1] TRUE TRUE FALSE FALSE
</code></pre>

And the <code>as.numeric()</code>-function applied to the value <code>1</code> will return exactly the input.

Further comment: Since your attempted use of "==" was really as an implicit set operation, you might want to review the help page for <code>?intersect</code>. There're also packages that handle more sophisticated set functions.

R's coercion can go back and forth between logical and numeric depending on how functions are defined:

<pre><code>sum( letters[1:10] %in% letters)
[1] 10

sum( letters[1:10] == letters)
[1] 10
Warning message:
In letters[1:10] == letters :
 longer object length is not a multiple of shorter object length
</code></pre>

I wanted to make a simple comparison using <code>h == 1 | 2</code> where <code>h</code> could be an integer between 1 and 4. To my astonishment, it didn't work.
I could sort of understand why
<blockquote>
1 == 2 | 4
TRUE
</blockquote>
and perhaps even why
<blockquote>
1 == (2 | 4)
TRUE
</blockquote>
but why in the name of all that's reasonable and sane does
<blockquote>
as.numeric(1) == (2 | 4)
</blockquote>
or
<blockquote>
1L == (2 | 4)
</blockquote>
or
<blockquote>
3 == 2 | 4
</blockquote>
evaluate to
<blockquote>
TRUE
</blockquote>
???
How can I ask R to tell me whether <code>1 is equal to 2 or 4</code> and the answer will be <code>FALSE</code>?

Why does as.numeric(1) == (3 | 4) evaluate to TRUE?

我想用h == 1 | 2做一个简单的比较，h可以是1到4之间的整数。令我惊讶的是，它不起作用。我大概能理解为什么 1 == 2|4真的甚至可能是为什么 1 == (2 | 4)真的但为什么以一切合理和理智的名义 as.numeric(%1) == (%2| 4)或 1L == (2 | 4)或 3 == 2|4评估结...

问为什么as.numeric(1) == (3 | 4)求值为TRUE？
EN

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问为什么as.numeric(1) == (3 | 4)求值为TRUE？EN

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问为什么as.numeric(1) == (3 | 4)求值为TRUE？
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