blocks|key|867422|text|array_merge是一种优雅的方式：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|867423|$a+=+array('a',+'b');
$b+=+array('c',+'d');
$merge+=+array_merge($a,+$b);+
//+$merge+is+now+equals+to+array('a','b','c','d');|code-block|syntax|javascript|867424|做一些类似的事情：|867425|$merge+=+$a+%2B+$b;
//+$merge+now+equals+array('a','b')|867426|将不起作用，因为%2B运算符实际上并不合并它们。如果它们的$a与$b具有相同的密钥，它将不会执行任何操作。|867427|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/function.array-merge.php^0|0|B|0|B|0|0|0|0|0|8|1|R|2|U|2|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@$9|11|A|12|1|13]]|E|$]]|$1|F|3|G|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|15|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|X]]]]

<a href="http://php.net/manual/en/function.array-merge.php" rel="noreferrer"><code>array_merge</code></a> is the elegant way:

<pre><code>$a = array('a', 'b');
$b = array('c', 'd');
$merge = array_merge($a, $b); 
// $merge is now equals to array('a','b','c','d');
</code></pre>

Doing something like:

<pre><code>$merge = $a + $b;
// $merge now equals array('a','b')
</code></pre>

Will not work, because the <code>+</code> operator does not actually merge them. If they <code>$a</code> has the same keys as <code>$b</code>, it won't do anything.

blocks|key|1082100|text|为什么不使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082101|$appended+=+array_merge($a,$b);+|code-block|syntax|javascript|1082102|你为什么不使用这个，正确的，内置的方法。|1082103|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|$]]

Why not use

<pre><code>$appended = array_merge($a,$b); 
</code></pre>

Why don't you want to use this, the correct, built-in method.

blocks|key|867447|text|对于大型数组，最好不使用array_merge进行连接，以避免内存复制。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|867448|$array1+=+array_fill(0,50000,'aa');
$array2+=+array_fill(0,100,'bb');

//+Test+1+(array_merge)
$start+=+microtime(true);
$r1+=+array_merge($array1,+$array2);
echo+sprintf("Test+1:+%25.06f\n",+microtime(true)+-+$start);

//+Test2+(avoid+copy)
$start+=+microtime(true);
foreach+($array2+as+$v)+{
++++$array1[]+=+$v;
}
echo+sprintf("Test+2:+%25.06f\n",+microtime(true)+-+$start);


//+Test+1:+0.004963
//+Test+2:+0.000038|code-block|syntax|javascript|867449|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|$]]

For big array, is better to concatenate without array_merge, for avoid a memory copy.

<pre><code>$array1 = array_fill(0,50000,'aa');
$array2 = array_fill(0,100,'bb');

// Test 1 (array_merge)
$start = microtime(true);
$r1 = array_merge($array1, $array2);
echo sprintf("Test 1: %.06f\n", microtime(true) - $start);

// Test2 (avoid copy)
$start = microtime(true);
foreach ($array2 as $v) {
 $array1[] = $v;
}
echo sprintf("Test 2: %.06f\n", microtime(true) - $start);


// Test 1: 0.004963
// Test 2: 0.000038
</code></pre>

blocks|key|867510|text|在bstoney和Snark的回答之后，我对各种方法进行了一些测试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|867511|//+Test+1+(array_merge)
$array1+=+$array2+=+array_fill(0,+50000,+'aa');
$start+=+microtime(true);
$array1+=+array_merge($array1,+$array2);
echo+sprintf("Test+1:+%25.06f\n",+microtime(true)+-+$start);

//+Test2+(foreach)
$array1+=+$array2+=+array_fill(0,+50000,+'aa');
$start+=+microtime(true);
foreach+($array2+as+$v)+{
++++$array1[]+=+$v;
}
echo+sprintf("Test+2:+%25.06f\n",+microtime(true)+-+$start);

//+Test+3+(...+token)
//+PHP+5.6%2B+and+produces+error+if+$array2+is+empty
$array1+=+$array2+=+array_fill(0,+50000,+'aa');
$start+=+microtime(true);
array_push($array1,+...$array2);
echo+sprintf("Test+3:+%25.06f\n",+microtime(true)+-+$start);|code-block|syntax|javascript|867512|这会产生：|867513|Test+1:+0.002717+
Test+2:+0.006922+
Test+3:+0.004744|867514|原始:我认为在PHP7中，方法3是一种明显更好的替代方法，这是由于foreach+loops+now+act的方式，即对要迭代的数组进行复制。|offset|length|867515|虽然方法3没有严格地回答问题中的“not+array_push”标准，但它是一行，并且在所有方面都是最高性能的，我认为这个问题是在...语法是一种选择。|867516|UPDATE+25/03/2020:我更新了测试，因为变量没有重置，所以测试有缺陷。有趣的(或令人困惑的)结果现在显示测试1是最快的，它是最慢的，从0.008392到0.002717！这只能归结到PHP更新，因为这不会受到测试缺陷的影响。|867517|所以，传奇还在继续，我将从现在开始使用array_merge！|867518|entityMap|0|LINK|mutability|MUTABLE|url|http://php.net/manual/en/migration70.incompatible.php#migration70.incompatible.foreach^0|0|0|0|0|X|L|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|14|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|16|8|@]|9|@$M|17|N|18|1|19]]|A|$]]|$1|O|3|P|5|6|7|1A|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|1B|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1C|8|@]|9|@]|A|$]]|$1|U|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]]]

Following on from answer's by bstoney and Snark I did some tests on the various methods:

<pre><code>// Test 1 (array_merge)
$array1 = $array2 = array_fill(0, 50000, 'aa');
$start = microtime(true);
$array1 = array_merge($array1, $array2);
echo sprintf("Test 1: %.06f\n", microtime(true) - $start);

// Test2 (foreach)
$array1 = $array2 = array_fill(0, 50000, 'aa');
$start = microtime(true);
foreach ($array2 as $v) {
 $array1[] = $v;
}
echo sprintf("Test 2: %.06f\n", microtime(true) - $start);

// Test 3 (... token)
// PHP 5.6+ and produces error if $array2 is empty
$array1 = $array2 = array_fill(0, 50000, 'aa');
$start = microtime(true);
array_push($array1, ...$array2);
echo sprintf("Test 3: %.06f\n", microtime(true) - $start);
</code></pre>

Which produces:

<pre><code>Test 1: 0.002717 
Test 2: 0.006922 
Test 3: 0.004744
</code></pre>

ORIGINAL: I believe as of PHP 7, method 3 is a significantly better alternative due to the way <a href="http://php.net/manual/en/migration70.incompatible.php#migration70.incompatible.foreach" rel="nofollow noreferrer">foreach loops now act</a>, which is to make a copy of the array being iterated over.

Whilst method 3 isn't strictly an answer to the criteria of 'not array_push' in the question, it is one line and the most high performance in all respects, I think the question was asked before the ... syntax was an option.

UPDATE 25/03/2020:
I've updated the test which was flawed as the variables weren't reset. Interestingly (or confusingly) the results now show as test 1 being the fastest, where it was the slowest, having gone from 0.008392 to 0.002717! This can only be down to PHP updates, as this wouldn't have been affected by the testing flaw.

So, the saga continues, I will start using array_merge from now on!

blocks|key|1082308|text|在PHP7之前，您可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082309|array_splice($a,+count($a),+0,+$b);|code-block|syntax|javascript|1082310|array_splice()根据数组(第一个参数)进行操作，并将数组(第四个参数)值放在从第二个参数开始的值列表和第三个参数的数量的位置。当我们将第二个参数设置为源数组的末尾，将第三个参数设置为零时，我们将第四个参数的值附加到第一个参数|offset|length|style|CODE|1082311|entityMap^0|0|0|0|E|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]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Before PHP7 you can use:

<pre><code>array_splice($a, count($a), 0, $b);
</code></pre>

<code>array_splice()</code> operates with reference to array (1st argument) and puts array (4th argument) values in place of list of values started from 2nd argument and number of 3rd argument. When we set 2nd argument as end of source array and 3rd as zero we append 4th argument values to 1st argument

blocks|key|1082263|text|如果要将空数组与现有新值合并。您必须先对其进行初始化。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082264|$products+=+array();
//just+example
for($brand_id=1;$brand_id<=3;$brand_id%2B%2B){
++array_merge($products,getByBrand($brand_id));
}
//+it+will+create+empty+array
print_r($a);

//check+if+array+of+products+is+empty
for($brand_id=1;$brand_id<=3;$brand_id%2B%2B){
++if(empty($products)){
++++$products+=+getByBrand($brand_id);
++}else{
++++array_merge($products,getByBrand($brand_id));
++}
}
//+it+will+create+array+of+products|code-block|syntax|javascript|1082265|希望能有所帮助。|1082266|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|$]]

if you want to merge empty array with existing new value. You must initialize it first.

<pre><code>$products = array();
//just example
for($brand_id=1;$brand_id&lt;=3;$brand_id++){
 array_merge($products,getByBrand($brand_id));
}
// it will create empty array
print_r($a);

//check if array of products is empty
for($brand_id=1;$brand_id&lt;=3;$brand_id++){
 if(empty($products)){
 $products = getByBrand($brand_id);
 }else{
 array_merge($products,getByBrand($brand_id));
 }
}
// it will create array of products
</code></pre>

Hope its help.

blocks|key|1082379|text|在将值追加到现有数组中时，foreach循环比array_merge更快，因此，如果要将一个数组添加到另一个数组的末尾，请选择该循环。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082380|//+Create+an+array+of+arrays
$chars+=+[];
for+($i+=+0;+$i+<+15000;+$i%2B%2B)+{
++++$chars[]+=+array_fill(0,+10,+'a');
}

//+test+array_merge
$new+=+[];
$start+=+microtime(TRUE);
foreach+($chars+as+$splitArray)+{
++++$new+=+array_merge($new,+$splitArray);
}
echo+microtime(true)+-+$start;+//+=>+14.61776+sec

//+test+foreach
$new+=+[];
$start+=+microtime(TRUE);
foreach+($chars+as+$splitArray)+{
++++foreach+($splitArray+as+$value)+{
++++++++$new[]+=+$value;
++++}
}
echo+microtime(true)+-+$start;+//+=>+0.00900101+sec
//+==>+1600+times+faster|code-block|syntax|javascript|1082381|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|$]]

foreach loop is faster than array_merge to append values to an existing array, so choose the loop instead if you want to add an array to the end of another.

<pre><code>// Create an array of arrays
$chars = [];
for ($i = 0; $i &lt; 15000; $i++) {
 $chars[] = array_fill(0, 10, 'a');
}

// test array_merge
$new = [];
$start = microtime(TRUE);
foreach ($chars as $splitArray) {
 $new = array_merge($new, $splitArray);
}
echo microtime(true) - $start; // =&gt; 14.61776 sec

// test foreach
$new = [];
$start = microtime(TRUE);
foreach ($chars as $splitArray) {
 foreach ($splitArray as $value) {
 $new[] = $value;
 }
}
echo microtime(true) - $start; // =&gt; 0.00900101 sec
// ==&gt; 1600 times faster
</code></pre>

blocks|key|1082066|text|这样如何：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1082067|$appended+=+$a+%2B+$b;|code-block|syntax|javascript|1082068|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|$]]

How about this:

<pre><code>$appended = $a + $b;
</code></pre>

How to append one array to another without comparing their keys?

<pre><code>$a = array( 'a', 'b' );
$b = array( 'c', 'd' );
</code></pre>

At the end it should be: <code>Array( [0]=&gt;a [1]=&gt;b [2]=&gt;c [3]=&gt;d )</code>
If I use something like <code>[]</code> or <code>array_push</code>, it will cause one of these results:

<pre><code>Array( [0]=&gt;a [1]=&gt;b [2]=&gt;Array( [0]=&gt;c [1]=&gt;d ) )
//or
Array( [0]=&gt;c [1]=&gt;d )
</code></pre>

It just should be something, doing this, but in a more elegant way:

<pre><code>foreach ( $b AS $var )
 $a[] = $var;
</code></pre>

PHP append one array to another (not array_push or +)

如何在不比较数组键的情况下将一个数组追加到另一个数组？$a = array( 'a', 'b' );$b = array( 'c', 'd' );最后应该是：Array( [0]=>a [1]=>b [2]=>c [3]=>d )如果我使用像[]或array_push这样的东西，它将导致以下结果之一：Array( [0]=>a [1]=>b [2]=>Array( [0]=>c [1]=>d ) 

问将一个数组追加到另一个数组(不是array_push或+)
EN

回答 8

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将一个数组追加到另一个数组(不是array_push或+)EN

回答 8

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将一个数组追加到另一个数组(不是array_push或+)
EN