blocks|key|381042|text|你想要grepl|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|381043|>+chars+<-+"test"
>+value+<-+"es"
>+grepl(value,+chars)
[1]+TRUE
>+chars+<-+"test"
>+value+<-+"et"
>+grepl(value,+chars)
[1]+FALSE|code-block|syntax|javascript|381044|entityMap^0|3|5|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You want <code>grepl</code>:

<pre><code>&gt; chars &lt;- "test"
&gt; value &lt;- "es"
&gt; grepl(value, chars)
[1] TRUE
&gt; chars &lt;- "test"
&gt; value &lt;- "et"
&gt; grepl(value, chars)
[1] FALSE
</code></pre>

blocks|key|381069|text|使用grepl函数|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|381070|grepl(+needle,+haystack,+fixed+=+TRUE)|code-block|syntax|javascript|381071|如下所示：|381072|grepl(value,+chars,+fixed+=+TRUE)
#+TRUE|381073|使用?grepl了解更多信息。|381074|entityMap^0|2|5|0|0|0|0|2|6|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

Use the <code>grepl</code> function
<pre><code>grepl( needle, haystack, fixed = TRUE)
</code></pre>
like so:
<pre><code>grepl(value, chars, fixed = TRUE)
# TRUE
</code></pre>
Use <code>?grepl</code> to find out more.

blocks|key|381085|text|您可以使用grep|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|381086|grep("es",+"Test")
[1]+1
grep("et",+"Test")
integer(0)|code-block|syntax|javascript|381087|entityMap^0|5|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

You can use <code>grep</code>

<pre><code>grep("es", "Test")
[1] 1
grep("et", "Test")
integer(0)
</code></pre>

blocks|key|381110|text|使用stringi包中的函数：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|381111|>+stri_detect_fixed("test",c("et","es"))
[1]+FALSE++TRUE|code-block|syntax|javascript|381112|一些基准测试：|381113|library(stringi)
set.seed(123L)
value+<-+stri_rand_strings(10000,+ceiling(runif(10000,+1,+100)))+#+10000+random+ASCII+strings
head(value)

chars+<-+"es"
library(microbenchmark)
microbenchmark(
+++grepl(chars,+value),
+++grepl(chars,+value,+fixed=TRUE),
+++grepl(chars,+value,+perl=TRUE),
+++stri_detect_fixed(value,+chars),
+++stri_detect_regex(value,+chars)
)
##+Unit:+milliseconds
##+++++++++++++++++++++++++++++++expr+++++++min++++++++lq++++median++++++++uq+++++++max+neval
##++++++++++++++++grepl(chars,+value)+13.682876+13.943184+14.057991+14.295423+15.443530+++100
##++grepl(chars,+value,+fixed+=+TRUE)++5.071617++5.110779++5.281498++5.523421+45.243791+++100
##+++grepl(chars,+value,+perl+=+TRUE)++1.835558++1.873280++1.956974++2.259203++3.506741+++100
##++++stri_detect_fixed(value,+chars)++1.191403++1.233287++1.309720++1.510677++2.821284+++100
##++++stri_detect_regex(value,+chars)++6.043537++6.154198++6.273506++6.447714++7.884380+++100|381114|entityMap^0|2|7|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

Use this function from <code>stringi</code> package:

<pre><code>&gt; stri_detect_fixed("test",c("et","es"))
[1] FALSE TRUE
</code></pre>

Some benchmarks:

<pre><code>library(stringi)
set.seed(123L)
value &lt;- stri_rand_strings(10000, ceiling(runif(10000, 1, 100))) # 10000 random ASCII strings
head(value)

chars &lt;- "es"
library(microbenchmark)
microbenchmark(
 grepl(chars, value),
 grepl(chars, value, fixed=TRUE),
 grepl(chars, value, perl=TRUE),
 stri_detect_fixed(value, chars),
 stri_detect_regex(value, chars)
)
## Unit: milliseconds
## expr min lq median uq max neval
## grepl(chars, value) 13.682876 13.943184 14.057991 14.295423 15.443530 100
## grepl(chars, value, fixed = TRUE) 5.071617 5.110779 5.281498 5.523421 45.243791 100
## grepl(chars, value, perl = TRUE) 1.835558 1.873280 1.956974 2.259203 3.506741 100
## stri_detect_fixed(value, chars) 1.191403 1.233287 1.309720 1.510677 2.821284 100
## stri_detect_regex(value, chars) 6.043537 6.154198 6.273506 6.447714 7.884380 100
</code></pre>

blocks|key|381164|text|如果你还想检查一个字符串(或一组字符串)是否包含多个子串，你也可以在两个子串之间使用'%7C‘。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|381165|>substring="as%7Cat"
>string_vector=c("ass","ear","eye","heat")+
>grepl(substring,string_vector)|code-block|syntax|javascript|381166|你会得到|381167|[1]++TRUE+FALSE+FALSE++TRUE|381168|因为第一个单词有子字符串"as"，最后一个单词包含子字符串"at“|381169|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Just in case you would also like check if a string (or a set of strings) contain(s) multiple sub-strings, you can also use the '|' between two substrings.

<pre><code>&gt;substring="as|at"
&gt;string_vector=c("ass","ear","eye","heat") 
&gt;grepl(substring,string_vector)
</code></pre>

You will get

<pre><code>[1] TRUE FALSE FALSE TRUE
</code></pre>

since the 1st word has substring "as", and the last word contains substring "at"

I'm trying to determine if a string is a subset of another string. For example:

<pre><code>chars &lt;- "test"
value &lt;- "es"
</code></pre>

I want to return TRUE if "value" appears as part of the string "chars". In the following scenario, I would want to return false:

<pre><code>chars &lt;- "test"
value &lt;- "et"
</code></pre>

Test if characters are in a string

我正在尝试确定一个字符串是否是另一个字符串的子集。例如：chars <- "test"value <- "es"如果"value“作为字符串"chars”的一部分出现，我想返回TRUE。在下面的场景中，我想返回false：chars <- "test"value <- "et"

问测试字符是否在字符串中
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