blocks|key|3094411|text|关于Android的使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3094412|android.text.TextUtils.join(",",+ids);|code-block|syntax|javascript|3094413|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|$]]

On Android use: 

<pre><code>android.text.TextUtils.join(",", ids);
</code></pre>

blocks|key|226021|text|使用Java+8：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|226022|String+csv+=+String.join(",",+ids);|code-block|syntax|javascript|226023|对于Java7-，有一种很脏的方法(注意:只有当你不在你的list中插入包含+",+"+的字符串时，它才有效)-显然，List#toString将执行一个循环来创建idList，但它不会出现在你的代码中：|offset|length|style|BOLD|CODE|226024|List<String>+ids+=+new+ArrayList<String>();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
String+idList+=+ids.toString();
String+csv+=+idList.substring(1,+idList.length()+-+1).replace(",+",+",");|226025|entityMap^0|0|0|I|K|13|4|13|4|1N|D|2A|6|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|T|8|@$I|U|J|V|K|L]|$I|W|J|X|K|L]|$I|Y|J|Z|K|M]|$I|10|J|11|K|M]|$I|12|J|13|K|M]]|9|@]|A|$]]|$1|N|3|O|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|P|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|Q|$]]

With Java 8:

<pre><code>String csv = String.join(",", ids);
</code></pre>

With Java 7-, there is a dirty way (note: it works only if you don't insert strings which contain <code>", "</code> in your list) - obviously, <code>List#toString</code> will perform a loop to create <code>idList</code> but it does not appear in your code:

<pre><code>List&lt;String&gt; ids = new ArrayList&lt;String&gt;();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
String idList = ids.toString();
String csv = idList.substring(1, idList.length() - 1).replace(", ", ",");
</code></pre>

blocks|key|2880165|text|import+com.google.common.base.Joiner;

Joiner.on(",").join(ids);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2880166|或者，您可以使用StringUtils|unstyled|offset|length|style|BOLD|2880167|+++public+static+String+join(Object[]+array,
++++++++++++++++++++++++++++++char+separator)

+++public+static+String+join(Iterable<?>+iterator,
++++++++++++++++++++++++++++++char+separator)|2880168|将所提供的array/iterable的元素连接到包含所提供的元素列表的单个字符串中。|2880169|http://commons.apache.org/proper/commons-lang/javadocs/api-3.3.2/org/apache/commons/lang3/StringUtils.html|2880170|entityMap|0|LINK|mutability|MUTABLE|url^0|0|8|B|0|0|0|0|2Y|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|Y|8|@$G|Z|H|10|I|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|11|8|@]|9|@]|A|$B|C]]|$1|M|3|N|5|F|7|12|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|13|8|@]|9|@$G|14|H|15|1|16]]|A|$]]|$1|Q|3|-4|5|F|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|P]]]]

<pre><code>import com.google.common.base.Joiner;

Joiner.on(",").join(ids);
</code></pre>

or you can use StringUtils:

<pre><code> public static String join(Object[] array,
 char separator)

 public static String join(Iterable&lt;?&gt; iterator,
 char separator)
</code></pre>

Joins the elements of the provided array/iterable into a single String containing the provided list of elements.

<a href="http://commons.apache.org/proper/commons-lang/javadocs/api-3.3.2/org/apache/commons/lang3/StringUtils.html" rel="noreferrer">http://commons.apache.org/proper/commons-lang/javadocs/api-3.3.2/org/apache/commons/lang3/StringUtils.html</a>

blocks|key|228275|text|如果要将列表转换为CSV格式，请执行操作.........|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|228276|List<String>+ids+=+new+ArrayList<String>();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");

//+CSV+format
String+csv+=+ids.toString().replace("[",+"").replace("]",+"")
++++++++++++.replace(",+",+",");

//+CSV+format+surrounded+by+single+quote+
//+Useful+for+SQL+IN+QUERY

String+csvWithQuote+=+ids.toString().replace("[",+"'").replace("]",+"'")
++++++++++++.replace(",+",+"','");|code-block|syntax|javascript|228277|entityMap^0|I|B|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|$]]

If you want to convert list into the CSV format ......... 

<pre><code>List&lt;String&gt; ids = new ArrayList&lt;String&gt;();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");

// CSV format
String csv = ids.toString().replace("[", "").replace("]", "")
 .replace(", ", ",");

// CSV format surrounded by single quote 
// Useful for SQL IN QUERY

String csvWithQuote = ids.toString().replace("[", "'").replace("]", "'")
 .replace(", ", "','");
</code></pre>

blocks|key|226072|text|最快的方法是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|226073|StringUtils.join(ids,+",");|code-block|syntax|javascript|226074|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|$]]

The quickest way is 

<pre><code>StringUtils.join(ids, ",");
</code></pre>

blocks|key|223212|text|以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|223213|String+joinedString+=+ids.toString()|code-block|syntax|javascript|223214|将为您提供一个逗号分隔的列表。See+docs+for+details。|offset|length|223215|您将需要做一些后处理来删除方括号，但不要太复杂。|223216|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.oracle.com/javase/9/docs/api/java/util/AbstractCollection.html#toString--^0|0|0|F|K|0|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]]|$1|G|3|H|5|6|7|W|8|@]|9|@$I|X|J|Y|1|Z]]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

The following:

<pre><code>String joinedString = ids.toString()
</code></pre>

will give you a comma delimited list. <a href="https://docs.oracle.com/javase/9/docs/api/java/util/AbstractCollection.html#toString--" rel="noreferrer">See docs for details</a>.

You will need to do some post-processing to remove the square brackets, but nothing too tricky.

blocks|key|2880373|text|一个(纯Java+Liner+)|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2880374|list.toString().replace(",+",+",").replaceAll("[\\[.\\]]",+"");|code-block|syntax|javascript|2880375|entityMap^0|3|D|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|$]]

One Liner (pure Java)

<pre><code>list.toString().replace(", ", ",").replaceAll("[\\[.\\]]", "");
</code></pre>

blocks|key|228394|text|ArrayList上的Join+/+concat和Split函数|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|228395|To++/concat++arraylist的所有元素使用逗号+("，")连接到字符串。|228396|List<String>+ids+=+new+ArrayList<String>();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
String+allIds+=+TextUtils.join(",",+ids);
Log.i("Result",+allIds);|code-block|syntax|javascript|228397|使用逗号+("，")将字符串的所有元素拆分为数组列表。|228398|String+allIds+=+"1,2,3,4";
String[]+allIdsArray+=+TextUtils.split(allIds,+",");
ArrayList<String>+idsList+=+new+ArrayList<String>(Arrays.asList(allIdsArray));
for(String+element+:+idsList){
++++Log.i("Result",+element);
}|228399|Done|228400|entityMap^0|B|D|P|5|0|3|8|C|J|Y|1|0|0|2|2|7|1|0|0|0|4|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|16|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|1C|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1D|8|@$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|S|3|-4|5|6|7|1G|8|@]|D|@]|E|$]]]|T|$]]

Join / concat &amp; Split functions on ArrayList:

To Join /concat all elements of arraylist with comma (",") to String.

<pre><code>List&lt;String&gt; ids = new ArrayList&lt;String&gt;();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
String allIds = TextUtils.join(",", ids);
Log.i("Result", allIds);
</code></pre>

To split all elements of String to arraylist with comma (",").

<pre><code>String allIds = "1,2,3,4";
String[] allIdsArray = TextUtils.split(allIds, ",");
ArrayList&lt;String&gt; idsList = new ArrayList&lt;String&gt;(Arrays.asList(allIdsArray));
for(String element : idsList){
 Log.i("Result", element);
}
</code></pre>

Done

blocks|key|228314|text|我有字符串的ArrayList，我需要将它转换成逗号分隔的列表，不带空格。ArrayList+toString()方法添加了方括号、逗号和空格。我尝试了正则表达式方法，如下所示。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|228315|List<String>+myProductList+=+new+ArrayList<String>();
myProductList.add("sanjay");
myProductList.add("sameer");
myProductList.add("anand");
Log.d("TEST1",+myProductList.toString());+++++//+"[sanjay,+sameer,+anand]"
String+patternString+=+myProductList.toString().replaceAll("[\\s\\[\\]]",+"");
Log.d("TEST",+patternString);+++++++++++++++++//+"sanjay,sameer,anand"|code-block|syntax|javascript|228316|请评论以获得更好的高效逻辑。(代码适用于Android+/+Java+)|228317|谢谢。|228318|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]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I am having ArrayList of String, which I need to convert to comma separated list, without space. The ArrayList toString() method adds square brackets, comma and space. I tried the Regular Expression method as under.

<pre><code>List&lt;String&gt; myProductList = new ArrayList&lt;String&gt;();
myProductList.add("sanjay");
myProductList.add("sameer");
myProductList.add("anand");
Log.d("TEST1", myProductList.toString()); // "[sanjay, sameer, anand]"
String patternString = myProductList.toString().replaceAll("[\\s\\[\\]]", "");
Log.d("TEST", patternString); // "sanjay,sameer,anand"
</code></pre>

Please comment for more better efficient logic.
( The code is for Android / Java )

Thankx.

blocks|key|226672|text|如果不是字符串集合，则使用Java+8解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|226673|{Any+collection}.stream()
++++.collect(StringBuilder::new,+StringBuilder::append,+StringBuilder::append)
++++.toString()|code-block|syntax|javascript|226674|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|$]]

Java 8 solution if it's not a collection of strings:

<pre><code>{Any collection}.stream()
 .collect(StringBuilder::new, StringBuilder::append, StringBuilder::append)
 .toString()
</code></pre>

blocks|key|2880487|text|如果object下面有属性，你可以使用下面的代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2880488|String+getCommonSeperatedString(List<ActionObject>+actionObjects)+{
++++StringBuffer+sb+=+new+StringBuffer();
++++for+(ActionObject+actionObject+:+actionObjects){
++++++++sb.append(actionObject.Id).append(",");
++++}
++++sb.deleteCharAt(sb.lastIndexOf(","));
++++return+sb.toString();
}|code-block|syntax|javascript|2880489|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|$]]

You can use below code if object has attibutes under it.

<pre><code>String getCommonSeperatedString(List&lt;ActionObject&gt; actionObjects) {
 StringBuffer sb = new StringBuffer();
 for (ActionObject actionObject : actionObjects){
 sb.append(actionObject.Id).append(",");
 }
 sb.deleteCharAt(sb.lastIndexOf(","));
 return sb.toString();
}
</code></pre>

blocks|key|228284|text|如果您使用的是Eclipse+Collections+(以前是GS集合)，则可以使用makeString()方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|228285|List<String>+ids+=+new+ArrayList<String>();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");

Assert.assertEquals("1,2,3,4",+ListAdapter.adapt(ids).makeString(","));|code-block|syntax|javascript|228286|如果您可以将ArrayList转换为FastList，您就可以摆脱适配器。|228287|Assert.assertEquals("1,2,3,4",+FastList.newListWith(1,+2,+3,+4).makeString(","));|228288|Eclipse：我是集合的提交者。|BOLD|228289|entityMap|0|LINK|mutability|MUTABLE|url|http://www.eclipse.org/collections/^0|16|C|7|J|0|0|0|6|9|I|8|0|0|8|2|0^^$0|@$1|2|3|4|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@$9|12|A|13|1|14]]|E|$]]|$1|F|3|G|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|16|8|@$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|1C|8|@$9|1D|A|1E|B|Q]]|D|@]|E|$]]|$1|R|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]]|S|$T|$5|U|V|W|E|$X|Y]]]]

If you're using <a href="http://www.eclipse.org/collections/" rel="nofollow noreferrer">Eclipse Collections</a> (formerly GS Collections), you can use the <code>makeString()</code> method.

<pre><code>List&lt;String&gt; ids = new ArrayList&lt;String&gt;();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");

Assert.assertEquals("1,2,3,4", ListAdapter.adapt(ids).makeString(","));
</code></pre>

If you can convert your <code>ArrayList</code> to a <code>FastList</code>, you can get rid of the adapter.

<pre><code>Assert.assertEquals("1,2,3,4", FastList.newListWith(1, 2, 3, 4).makeString(","));
</code></pre>

Note: I am a committer for Eclipse collections.

blocks|key|2880437|text|下面给出了将列表转换为逗号分隔字符串而不显式迭代列表的代码，因为您必须创建一个列表并在其中添加项目，然后将其转换为逗号分隔字符串|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2880438|此代码的输出将是:+Veeru，Nikhil，Ashish，Paritosh|2880439|代替列表Veeru、Nikhil、Ashish、Paritosh的输出|2880440|String+List_name;
List<String>+myNameList+=+new+ArrayList<String>();
myNameList.add("Veeru");
myNameList.add("Nikhil");
myNameList.add("Ashish");
myNameList.add("Paritosh");

List_name+=+myNameList.toString().replace("[",+"")
++++++++++++++++++++.replace("]",+"").replace(",+",+",");|code-block|syntax|javascript|2880441|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here is code given below to convert a List into a comma separated string without iterating List explicitly for that you have to make a list and add item in it than convert it into a comma separated string

Output of this code will be: Veeru,Nikhil,Ashish,Paritosh 

instead of output of list [Veeru,Nikhil,Ashish,Paritosh]

<pre><code>String List_name;
List&lt;String&gt; myNameList = new ArrayList&lt;String&gt;();
myNameList.add("Veeru");
myNameList.add("Nikhil");
myNameList.add("Ashish");
myNameList.add("Paritosh");

List_name = myNameList.toString().replace("[", "")
 .replace("]", "").replace(", ", ",");
</code></pre>

<pre><code>List&lt;String&gt; ids = new ArrayList&lt;String&gt;();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
</code></pre>

Now i want an output from this list as 1,2,3,4 without explicitly iterating over it.

How to convert a List<String> into a comma separated string without iterating List explicitly

Android

Eclipse

Java

List<String> ids = new ArrayList<String>();ids.add("1");ids.add("2");ids.add("3");ids.add("4");现在我希望这个列表的输出是1,2,3,4，没有显式地对它进行迭代。

问如何在不显式迭代列表的情况下将List<String>转换为逗号分隔的字符串
EN

回答 13

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问如何在不显式迭代列表的情况下将List<String>转换为逗号分隔的字符串EN

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问如何在不显式迭代列表的情况下将List<String>转换为逗号分隔的字符串
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