blocks|key|1222689|text|还有另一种解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1222690|#!/bin/bash
foo=('foo+bar'+'foo+baz'+'bar+baz')
bar=$(printf+",%25s"+"${foo[@]}")
bar=${bar:1}

echo+$bar|code-block|syntax|javascript|1222691|Edit:相同，但用于多字符可变长度分隔符：|1222692|#!/bin/bash
separator=")%7C("+#+e.g.+constructing+regex,+pray+it+does+not+contain+%25s
foo=('foo+bar'+'foo+baz'+'bar+baz')
regex="$(+printf+"${separator}%25s"+"${foo[@]}"+)"
regex="${regex:${#separator}}"+#+remove+leading+separator
echo+"${regex}"
#+Prints:+foo+bar)%7C(foo+baz)%7C(bar+baz|1222693|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Yet another solution:

<pre><code>#!/bin/bash
foo=('foo bar' 'foo baz' 'bar baz')
bar=$(printf ",%s" "${foo[@]}")
bar=${bar:1}

echo $bar
</code></pre>

Edit: same but for multi-character variable length separator:

<pre><code>#!/bin/bash
separator=")|(" # e.g. constructing regex, pray it does not contain %s
foo=('foo bar' 'foo baz' 'bar baz')
regex="$( printf "${separator}%s" "${foo[@]}" )"
regex="${regex:${#separator}}" # remove leading separator
echo "${regex}"
# Prints: foo bar)|(foo baz)|(bar baz
</code></pre>

blocks|key|1222756|text|$+foo=(a+"b+c"+d)
$+bar=$(IFS=,+;+echo+"${foo[*]}")
$+echo+"$bar"
a,b+c,d|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1222757|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

blocks|key|1222523|text|也许，例如，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1222524|SAVE_IFS="$IFS"
IFS=","
FOOJOIN="${FOO[*]}"
IFS="$SAVE_IFS"

echo+"$FOOJOIN"|code-block|syntax|javascript|1222525|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Maybe, e.g.,

<pre><code>SAVE_IFS="$IFS"
IFS=","
FOOJOIN="${FOO[*]}"
IFS="$SAVE_IFS"

echo "$FOOJOIN"
</code></pre>

blocks|key|1223510|text|令人惊讶的是，我的解决方案还没有给出:)这对我来说是最简单的方法。它不需要函数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1223511|IFS=,+eval+'joined="${foo[*]}"'|code-block|syntax|javascript|1223512|注意:观察到此解决方案在非POSIX模式下工作良好。在POSIX+mode中，元素仍然正确地连接在一起，但是IFS=,成为永久性的。|offset|length|style|CODE|1223513|entityMap|0|LINK|mutability|MUTABLE|url|https://www.gnu.org/software/bash/manual/html_node/Bash-POSIX-Mode.html^0|0|0|1I|5|R|A|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@$I|X|J|Y|K|L]]|9|@$I|Z|J|10|1|11]]|A|$]]|$1|M|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Surprisingly my solution is not yet given :) This is the simplest way for me. It doesn't need a function:

<pre><code>IFS=, eval 'joined="${foo[*]}"'
</code></pre>

Note: This solution was observed to work well in non-POSIX mode. In <a href="https://www.gnu.org/software/bash/manual/html_node/Bash-POSIX-Mode.html" rel="noreferrer">POSIX mode</a>, the elements are still joined properly, but <code>IFS=,</code> becomes permanent.

blocks|key|1437804|text|不使用外部命令：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1437805|$+FOO=(+a+b+c+)+++++#+initialize+the+array
$+BAR=${FOO[@]}+++++#+create+a+space+delimited+string+from+array
$+BAZ=${BAR//+/,}+++#+use+parameter+expansion+to+substitute+spaces+with+comma
$+echo+$BAZ
a,b,c|code-block|syntax|javascript|1437806|警告，它假定元素没有空格。|1437807|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Using no external commands:

<pre><code>$ FOO=( a b c ) # initialize the array
$ BAR=${FOO[@]} # create a space delimited string from array
$ BAZ=${BAR// /,} # use parameter expansion to substitute spaces with comma
$ echo $BAZ
a,b,c
</code></pre>

Warning, it assumes elements don't have whitespaces.

blocks|key|1438629|text|这与现有的解决方案没有太大的不同，但它避免了使用单独的函数，不会修改父shell中的IFS，并且全部在一行中：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1438630|arr=(a+b+c)
printf+'%25s\n'+"$(IFS=,;+printf+'%25s'+"${arr[*]}")"|code-block|syntax|javascript|1438631|结果是|1438632|a,b,c|1438633|限制:分隔符不能超过一个字符。|1438634|1438635|这可以简化为|1438636|(IFS=,;+printf+'%25s'+"${arr[*]}")|1438637|在这一点上，它基本上与Pascal's+answer相同，但使用printf而不是echo，并将结果打印到标准输出，而不是将其赋给变量。|1438638|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/9429887/3266847^0|16|3|0|0|0|0|0|0|0|0|W|6|15|4|B|F|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@$9|16|A|17|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|18|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|19|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|1A|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1B|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]|$1|R|3|S|5|6|7|1D|8|@]|D|@]|E|$]]|$1|T|3|U|5|H|7|1E|8|@]|D|@]|E|$I|J]]|$1|V|3|W|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]]|D|@$9|1K|A|1L|1|1M]]|E|$]]|$1|X|3|-4|5|6|7|1N|8|@]|D|@]|E|$]]]|Y|$Z|$5|10|11|12|E|$13|14]]]]

This isn't all too different from existing solutions, but it avoids using a separate function, doesn't modify <code>IFS</code> in the parent shell and is all in a single line:
<pre><code>arr=(a b c)
printf '%s\n' &quot;$(IFS=,; printf '%s' &quot;${arr[*]}&quot;)&quot;
</code></pre>
resulting in
<pre><code>a,b,c
</code></pre>
Limitation: the separator can't be longer than one character.
<hr />
This could be simplified to just
<pre class="lang-sh prettyprint-override"><code>(IFS=,; printf '%s' &quot;${arr[*]}&quot;)
</code></pre>
at which point it's basically the same as <a href="https://stackoverflow.com/a/9429887/3266847">Pascal's answer</a>, but using <code>printf</code> instead of <code>echo</code>, and printing the result to stdout instead of assigning it to a variable.

blocks|key|1438054|text|下面是一个100%25纯Bash函数，它可以完成这项工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1438055|join()+{
++++#+$1+is+return+variable+name
++++#+$2+is+sep
++++#+$3...+are+the+elements+to+join
++++local+retname=$1+sep=$2+ret=$3
++++shift+3+%7C%7C+shift+$(($#))
++++printf+-v+"$retname"+"%25s"+"$ret${@/#/$sep}"
}|code-block|syntax|javascript|1438056|看：|1438057|$+a=(+one+two+"three+three"+four+five+)
$+join+joineda+"+and+"+"${a[@]}"
$+echo+"$joineda"
one+and+two+and+three+three+and+four+and+five
$+join+joinedb+randomsep+"only+one+element"
$+echo+"$joinedb"
only+one+element
$+join+joinedc+randomsep
$+echo+"$joinedc"

$+a=(+$'+stuff+with\nnewlines\n'+$'and+trailing+newlines\n\n'+)
$+join+joineda+$'a+sep+with\nnewlines\n'+"${a[@]}"
$+echo+"$joineda"
+stuff+with
newlines
a+sep+with
newlines
and+trailing+newlines


$|1438058|这甚至保留了尾随的换行符，并且不需要子subshell来获得函数的结果。如果你不喜欢printf+-v+(你为什么不喜欢它？)并传递一个变量名，当然可以使用全局变量作为返回的字符串：|offset|length|style|CODE|1438059|join()+{
++++#+$1+is+sep
++++#+$2...+are+the+elements+to+join
++++#+return+is+in+global+variable+join_ret
++++local+sep=$1+IFS=
++++join_ret=$2
++++shift+2+%7C%7C+shift+$(($#))
++++join_ret%2B="${*/#/$sep}"
}|1438060|entityMap^0|0|0|0|0|16|9|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@$M|Z|N|10|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|12|8|@]|9|@]|A|$]]]|T|$]]

Here's a 100% pure Bash function that does the job:

<pre><code>join() {
 # $1 is return variable name
 # $2 is sep
 # $3... are the elements to join
 local retname=$1 sep=$2 ret=$3
 shift 3 || shift $(($#))
 printf -v "$retname" "%s" "$ret${@/#/$sep}"
}
</code></pre>

Look:

<pre><code>$ a=( one two "three three" four five )
$ join joineda " and " "${a[@]}"
$ echo "$joineda"
one and two and three three and four and five
$ join joinedb randomsep "only one element"
$ echo "$joinedb"
only one element
$ join joinedc randomsep
$ echo "$joinedc"

$ a=( $' stuff with\nnewlines\n' $'and trailing newlines\n\n' )
$ join joineda $'a sep with\nnewlines\n' "${a[@]}"
$ echo "$joineda"
 stuff with
newlines
a sep with
newlines
and trailing newlines


$
</code></pre>

This preserves even the trailing newlines, and doesn't need a subshell to get the result of the function. If you don't like the <code>printf -v</code> (why wouldn't you like it?) and passing a variable name, you can of course use a global variable for the returned string:

<pre><code>join() {
 # $1 is sep
 # $2... are the elements to join
 # return is in global variable join_ret
 local sep=$1 IFS=
 join_ret=$2
 shift 2 || shift $(($#))
 join_ret+="${*/#/$sep}"
}
</code></pre>

blocks|key|1438434|text|我会将数组作为字符串回显，然后将空格转换为换行符，然后使用paste将所有内容连接到一行中，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1438435|tr+"+"+"\n"+<<<+"$FOO"+%7C+paste+-sd+,+-|1438436|结果：|1438437|a,b,c|1438438|对我来说，这似乎是最快最干净的！|1438439|entityMap^0|T|5|0|0|12|0|0|0|5|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|Z|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|O|$]]

I would echo the array as a string, then transform the spaces into line feeds, and then use <code>paste</code> to join everything in one line like so:

<code>tr " " "\n" &lt;&lt;&lt; "$FOO" | paste -sd , -</code>

Results:

<code>a,b,c</code>

This seems to be the quickest and cleanest to me !

blocks|key|1437732|text|重用@无关紧要的解决方案，但通过避免${:1}替换和对中间变量的需要，使用one语句。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1437733|echo+$(printf+"%25s,"+"${LIST[@]}"+%7C+cut+-d+","+-f+1-${#LIST[@]}+)|code-block|syntax|javascript|1437734|printf有‘格式字符串可以根据需要重复使用，以满足参数。’在它的手册页中，以便记录字符串的连接。然后，技巧是使用列表长度来砍掉最后一个描述符，因为当字段计数时，cut将只保留列表的长度。|1437735|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

With re-use of @doesn't matters' solution, but with a one statement by avoiding the ${:1} substition and need of an intermediary variable.

<pre><code>echo $(printf "%s," "${LIST[@]}" | cut -d "," -f 1-${#LIST[@]} )
</code></pre>

printf has 'The format string is reused as often as necessary to satisfy the arguments.' in its man pages, so that the concatenations of the strings is documented. Then the trick is to use the LIST length to chop the last sperator, since cut will retain only the lenght of LIST as fields count.

blocks|key|1222893|text|s=$(IFS=,+eval+'echo+"${FOO[*]}"')|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1222894|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

blocks|key|1437940|text|printf解决方案，可以接受任意长度的分隔符(基于@+that答案)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1437941|#/!bin/bash
foo=('foo+bar'+'foo+baz'+'bar+baz')

sep=','+#+can+be+of+any+length
bar=$(printf+"${sep}%25s"+"${foo[@]}")
bar=${bar:${#sep}}

echo+$bar|code-block|syntax|javascript|1437942|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

printf solution that accept separators of any length (based on @doesn't matters answer)

<pre><code>#/!bin/bash
foo=('foo bar' 'foo baz' 'bar baz')

sep=',' # can be of any length
bar=$(printf "${sep}%s" "${foo[@]}")
bar=${bar:${#sep}}

echo $bar
</code></pre>

blocks|key|1438349|text|top答案的简短版本：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1438350|joinStrings()+{+local+a=("${@:3}");+printf+"%25s"+"$2${a[@]/#/$1}";+}|code-block|syntax|javascript|1438351|用法：|1438352|joinStrings+"$myDelimiter"+"${myArray[@]}"|1438353|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Shorter version of top answer:

<pre><code>joinStrings() { local a=("${@:3}"); printf "%s" "$2${a[@]/#/$1}"; }
</code></pre>

Usage:

<pre><code>joinStrings "$myDelimiter" "${myArray[@]}"
</code></pre>

blocks|key|1437753|text|$+set+a+'b+c'+d

$+history+-p+"$@"+%7C+paste+-sd,
a,b+c,d|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1437754|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$ set a 'b c' d

$ history -p "$@" | paste -sd,
a,b c,d
</code></pre>

blocks|key|1438758|text|x=${arr[*]//+/,}|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1438759|这是做这件事的最短方法。|1438760|例如，|1438761|#+ZSH:
arr=(1+"2+3"+4+5)
x=${"${arr[*]}"//+/,}
echo+$x++#+output:+1,2,3,4,5

#+ZSH/BASH:
arr=(1+"2+3"+4+5)
a=${arr[*]}
x=${a//+/,}
echo+$x++#+output:+1,2,3,4,5|code-block|syntax|javascript|1438762|entityMap^0|0|G|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|T|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|U|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|V|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

<code>x=${arr[*]// /,}</code>
This is the shortest way to do it.
Example,
<pre><code># ZSH:
arr=(1 &quot;2 3&quot; 4 5)
x=${&quot;${arr[*]}&quot;// /,}
echo $x # output: 1,2,3,4,5

# ZSH/BASH:
arr=(1 &quot;2 3&quot; 4 5)
a=${arr[*]}
x=${a// /,}
echo $x # output: 1,2,3,4,5
</code></pre>

blocks|key|1438942|text|这些解决方案中的许多(如果不是大多数)依赖于晦涩难懂的语法、令人费解的正则表达式技巧或对外部可执行文件的调用。我想提出一个简单的，仅bash的解决方案，它非常容易理解，并且在性能方面略低于最佳。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1438943|join_by+()+{
++++#+Argument+#1+is+the+separator.+It+can+be+multi-character.
++++#+Argument+#2,+3,+and+so+on,+are+the+elements+to+be+joined.
++++#+Usage:+join_by+",+"+"${array[@]}"
++++local+SEPARATOR="$1"
++++shift

++++local+F=0
++++for+x+in+"$@"
++++do
++++++++if+[[+F+-eq+1+]]
++++++++then
++++++++++++echo+-n+"$SEPARATOR"
++++++++else
++++++++++++F=1
++++++++fi
++++++++echo+-n+"$x"
++++done
++++echo
}|code-block|syntax|javascript|1438944|示例：|1438945|$+a=(+1+"2+2"+3+)
$+join_by+",+"+"${a[@]}"
1,+2+2,+3
$+|1438946|我想指出的是，任何使用/usr/bin/[或/usr/bin/printf的解决方案都比我的解决方案慢，因为我使用的是100%25纯bash。作为其性能的一个示例，这里有一个演示，其中我创建了一个包含1,000,000个随机整数的数组，然后用逗号将它们连接起来，并对其进行计时。|offset|length|style|CODE|1438947|$+eval+$(echo+-n+"a=(";+x=0+;+while+[[+x+-lt+1000000+]];+do+echo+-n+"+$RANDOM"+;+x=$((x%2B1));+done;+echo+"+)")
$+time+join_by+,+${a[@]}+>/dev/null
real++++0m8.590s
user++++0m8.591s
sys+++++0m0.000s
$+|1438948|entityMap^0|0|0|0|0|B|A|M|F|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Y|8|@$M|Z|N|10|O|P]|$M|11|N|12|O|P]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|S|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|T|$]]

Many, if not most, of these solutions rely on arcane syntax, brain-busting regex tricks, or calls to external executables. I would like to propose a simple, bash-only solution that is very easy to understand, and only slightly sub-optimal, performance-wise.
<pre><code>join_by () {
 # Argument #1 is the separator. It can be multi-character.
 # Argument #2, 3, and so on, are the elements to be joined.
 # Usage: join_by &quot;, &quot; &quot;${array[@]}&quot;
 local SEPARATOR=&quot;$1&quot;
 shift

 local F=0
 for x in &quot;$@&quot;
 do
 if [[ F -eq 1 ]]
 then
 echo -n &quot;$SEPARATOR&quot;
 else
 F=1
 fi
 echo -n &quot;$x&quot;
 done
 echo
}
</code></pre>
Example:
<pre><code>$ a=( 1 &quot;2 2&quot; 3 )
$ join_by &quot;, &quot; &quot;${a[@]}&quot;
1, 2 2, 3
$ 
</code></pre>
I'd like to point out that any solution that uses <code>/usr/bin/[</code> or <code>/usr/bin/printf</code> is inherently slower than my solution, since I use 100% pure bash. As an example of its performance, Here's a demo where I create an array with 1,000,000 random integers, then join them all with a comma, and time it.
<pre><code>$ eval $(echo -n &quot;a=(&quot;; x=0 ; while [[ x -lt 1000000 ]]; do echo -n &quot; $RANDOM&quot; ; x=$((x+1)); done; echo &quot; )&quot;)
$ time join_by , ${a[@]} &gt;/dev/null
real 0m8.590s
user 0m8.591s
sys 0m0.000s
$ 
</code></pre>

blocks|key|1222535|text|现在我使用的是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1222536|TO_IGNORE=(
++++E201+#+Whitespace+after+'('
++++E301+#+Expected+N+blank+lines,+found+M
++++E303+#+Too+many+blank+lines+(pep8+gets+confused+by+comments)
)
ARGS="--ignore+`echo+${TO_IGNORE[@]}+%7C+tr+'+'+','`"|code-block|syntax|javascript|1222537|它可以工作，但(在一般情况下)如果数组元素中有空格，则会发生可怕的崩溃。|1222538|(对于那些感兴趣的人，这是一个围绕pep8.py的包装器脚本)|offset|length|1222539|entityMap|0|LINK|mutability|MUTABLE|url|http://github.com/cburroughs/pep8.py^0|0|0|0|H|7|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

Right now I'm using:

<pre><code>TO_IGNORE=(
 E201 # Whitespace after '('
 E301 # Expected N blank lines, found M
 E303 # Too many blank lines (pep8 gets confused by comments)
)
ARGS="--ignore `echo ${TO_IGNORE[@]} | tr ' ' ','`"
</code></pre>

Which works, but (in the general case) will break horribly if array elements have a space in them.

(For those interested, this is a wrapper script around <a href="http://github.com/cburroughs/pep8.py" rel="nofollow noreferrer">pep8.py</a>)

blocks|key|1222968|text|如果您想要连接的元素不是一个数组，而只是一个空格分隔的字符串，您可以这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1222969|foo="aa+bb+cc+dd"
bar=`for+i+in+$foo;+do+printf+",'%25s'"+$i;+done`
bar=${bar:1}
echo+$bar
++++'aa','bb','cc','dd'|code-block|syntax|javascript|1222970|例如，我的用例是在我的shell脚本中传递了一些字符串，我需要使用它来运行SQL查询：|1222971|./my_script+"aa+bb+cc+dd"|1222972|在my_script中，我需要执行"SELECT+*+FROM+table+WHERE+name+In+('aa'，'bb'，'cc'，'dd')“。|1222973|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|$]]

In case the elements you want to join is not an array just a space separated string, you can do something like this:

<pre><code>foo="aa bb cc dd"
bar=`for i in $foo; do printf ",'%s'" $i; done`
bar=${bar:1}
echo $bar
 'aa','bb','cc','dd'
</code></pre>

for example, my use case is that some strings are passed in my shell script and I need to use this to run on a SQL query:

<pre><code>./my_script "aa bb cc dd"
</code></pre>

In my_script, I need to do "SELECT * FROM table WHERE name IN ('aa','bb','cc','dd'). Then above command will be useful.

blocks|key|1437973|text|我的尝试。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1437974|$+array=(one+two+"three+four"+five)
$+echo+"${array[0]}$(printf+"+SEP+%25s"+"${array[@]:1}")"
one+SEP+two+SEP+three+four+SEP+five|code-block|syntax|javascript|1437975|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

My attempt.

<pre><code>$ array=(one two "three four" five)
$ echo "${array[0]}$(printf " SEP %s" "${array[@]:1}")"
one SEP two SEP three four SEP five
</code></pre>

blocks|key|1438092|text|将perl用于多字符分隔符：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1438093|function+join+{
+++perl+-e+'$s+=+shift+@ARGV;+print+join($s,+@ARGV);'+"$@";+
}

join+',+'+a+b+c+#+a,+b,+c|code-block|syntax|javascript|1438094|或者一行：|1438095|perl+-le+'print+join(shift,+@ARGV);'+',+'+1+2+3
1,+2,+3|1438096|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Use perl for multicharacter separators:

<pre><code>function join {
 perl -e '$s = shift @ARGV; print join($s, @ARGV);' "$@"; 
}

join ', ' a b c # a, b, c
</code></pre>

Or in one line:

<pre><code>perl -le 'print join(shift, @ARGV);' ', ' 1 2 3
1, 2, 3
</code></pre>

blocks|key|1223776|text|如果在循环中构建数组，这里有一个简单的方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1223777|arr=()
for+x+in+$(some_cmd);+do
+++arr%2B=($x,)
done
arr[-1]=${arr[-1]%25,}
echo+${arr[*]}|code-block|syntax|javascript|1223778|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

If you build the array in a loop, here is a simple way:

<pre><code>arr=()
for x in $(some_cmd); do
 arr+=($x,)
done
arr[-1]=${arr[-1]%,}
echo ${arr[*]}
</code></pre>

blocks|key|1437534|text|这种方法处理值中的空格，但需要一个循环：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1437535|#!/bin/bash

FOO=(+a+b+c+)
BAR=""

for+index+in+${!FOO[*]}
do
++++BAR="$BAR,${FOO[$index]}"
done
echo+${BAR:1}|code-block|syntax|javascript|1437536|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This approach takes care of spaces within the values, but requires a loop:

<pre><code>#!/bin/bash

FOO=( a b c )
BAR=""

for index in ${!FOO[*]}
do
 BAR="$BAR,${FOO[$index]}"
done
echo ${BAR:1}
</code></pre>

blocks|key|1438153|text|也许我遗漏了一些明显的东西，因为我是bash/zsh的新手，但在我看来，您根本不需要使用printf。没有它也不会变得很难看。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1438154|join()+{
++separator=$1
++arr=$*
++arr=${arr:2}+#+throw+away+separator+and+following+space
++arr=${arr//+/$separator}
}|code-block|syntax|javascript|1438155|至少，到目前为止，它对我来说没有任何问题。|1438156|例如，假设我在我的~目录中，join+\%7C+*.sh输出utilities.sh%7Cplay.sh%7Cfoobar.sh。对我来说已经足够了。|1438157|编辑:这基本上是Nil+Geisweiller's+answer，但泛化为一个函数。|1438158|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/11360591/771275^0|18|6|0|0|0|9|1|E|C|S|U|0|8|O|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|D|@]|E|$]]|$1|M|3|N|5|6|7|13|8|@$9|14|A|15|B|C]|$9|16|A|17|B|C]|$9|18|A|19|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|1A|8|@]|D|@$9|1B|A|1C|1|1D]]|E|$]]|$1|Q|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]]]

Perhaps I'm missing something obvious, since I'm a newb to the whole bash/zsh thing, but it looks to me like you don't need to use <code>printf</code> at all. Nor does it get really ugly to do without.

<pre><code>join() {
 separator=$1
 arr=$*
 arr=${arr:2} # throw away separator and following space
 arr=${arr// /$separator}
}
</code></pre>

At least, it has worked for me thus far without issue.

For instance, <code>join \| *.sh</code>, which, let's say I'm in my <code>~</code> directory, outputs <code>utilities.sh|play.sh|foobar.sh</code>. Good enough for me.

EDIT: This is basically <a href="https://stackoverflow.com/a/11360591/771275">Nil Geisweiller's answer</a>, but generalized into a function.

blocks|key|1223895|text|下面是大多数兼容POSIX的shell支持的一个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1223896|join_by()+{
++++#+Usage:++join_by+"%7C%7C"+a+b+c+d
++++local+arg+arr=()+sep="$1"
++++shift
++++for+arg+in+"$@";+do
++++++++if+[+0+-lt+"${#arr[@]}"+];+then
++++++++++++arr%2B=("${sep}")
++++++++fi
++++++++arr%2B=("${arg}")+%7C%7C+break
++++done
++++printf+"%25s"+"${arr[@]}"
}|code-block|syntax|javascript|1223897|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here's one that most POSIX compatible shells support:

<pre><code>join_by() {
 # Usage: join_by "||" a b c d
 local arg arr=() sep="$1"
 shift
 for arg in "$@"; do
 if [ 0 -lt "${#arr[@]}" ]; then
 arr+=("${sep}")
 fi
 arr+=("${arg}") || break
 done
 printf "%s" "${arr[@]}"
}
</code></pre>

blocks|key|1438820|text|也许聚会来晚了，但这对我很管用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1438821|function+joinArray()+{
++local+delimiter="${1}"
++local+output="${2}"
++for+param+in+${@:3};+do
++++output="${output}${delimiter}${param}"
++done

++echo+"${output}"
}|code-block|syntax|javascript|1438822|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Perhaps late for the party, but this works for me:

<pre><code>function joinArray() {
 local delimiter="${1}"
 local output="${2}"
 for param in ${@:3}; do
 output="${output}${delimiter}${param}"
 done

 echo "${output}"
}
</code></pre>

blocks|key|1224199|text|我相信这是最短的解决方案，正如Benamin+W.已经提到的：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1224200|(IFS=,;+printf+%25s+"${a[*]}")|code-block|syntax|javascript|1224201|我想补充的是，如果使用zsh，您可以删除子subshell：|1224202|IFS=,+printf+%25s+"${a[*]}"|1224203|测试：|1224204|a=(1+'a+b'+3)
IFS=,+printf+%25s+"${a[*]}"
1,a+b,3|1224205|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/users/3266847/benjamin-w^0|F|A|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|15|8|@]|9|@]|C|$]]|$1|O|3|P|5|F|7|16|8|@]|9|@]|C|$G|H]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]]]

I believe this is the shortest solution, as <a href="https://stackoverflow.com/users/3266847/benjamin-w">Benamin W.</a> already mentioned:
<pre class="lang-sh prettyprint-override"><code>(IFS=,; printf %s &quot;${a[*]}&quot;)
</code></pre>
Wanted to add that if you use zsh, you can drop the subshell:
<pre class="lang-sh prettyprint-override"><code>IFS=, printf %s &quot;${a[*]}&quot;
</code></pre>
Test:
<pre><code>a=(1 'a b' 3)
IFS=, printf %s &quot;${a[*]}&quot;
1,a b,3
</code></pre>

blocks|key|1437622|text|liststr=""
for+item+in+list
do
++++liststr=$item,$liststr
done
LEN=`expr+length+$liststr`
LEN=`expr+$LEN+-+1`
liststr=${liststr:0:$LEN}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1437623|这也解决了末尾多余的逗号问题。我不是狂欢专家。只有我的2c，因为这更基本，更容易理解。|unstyled|1437624|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>liststr=""
for item in list
do
 liststr=$item,$liststr
done
LEN=`expr length $liststr`
LEN=`expr $LEN - 1`
liststr=${liststr:0:$LEN}
</code></pre>

This takes care of the extra comma at the end also. I am no bash expert. Just my 2c, since this is more elementary and understandable

blocks|key|1223062|text|awk+-v+sep=.+'BEGIN{ORS=OFS="";for(i=1;i<ARGC;i%2B%2B){print+ARGV[i],ARGC-i-1?sep:""}}'+"${arr[@]}"|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1223063|或|unstyled|1223064|$+a=(1+"a+b"+3)
$+b=$(IFS=,+;+echo+"${a[*]}")
$+echo+$b
1,a+b,3|1223065|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>awk -v sep=. 'BEGIN{ORS=OFS="";for(i=1;i&lt;ARGC;i++){print ARGV[i],ARGC-i-1?sep:""}}' "${arr[@]}"
</code></pre>

or

<pre><code>$ a=(1 "a b" 3)
$ b=$(IFS=, ; echo "${a[*]}")
$ echo $b
1,a b,3
</code></pre>

If I have an array like this in Bash:

<pre><code>FOO=( a b c )
</code></pre>

How do I join the elements with commas? For example, producing <code>a,b,c</code>.

How can I join elements of an array in Bash?

如果我在Bash中有一个像这样的数组：FOO=( a b c )如何用逗号连接元素？例如，生成a,b,c。

问如何在Bash中连接数组的元素？
EN

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问如何在Bash中连接数组的元素？
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