PHP returns a string composed of array elements function implode()

Example

Combine array elements into a string:

<?php
$arr = array(&#39;Hello&#39;,&#39;World!&#39;,&#39;Beautiful&#39;,&#39;Day!&#39;);
echo implode(" ",$arr);
?>

Definition and usage

implode() function returns a string composed of array elements.

Note: The implode() function accepts two parameter orders. However, due to historical reasons, explode() does not work. You must ensure that the separator parameter comes before the string parameter.

Note: The separator parameter of the implode() function is optional. However, for backward compatibility, it is recommended that you use two parameters.

Note: This function is binary safe.

Syntax

implode(separator,array)

Parameters                 Description

separator                                                                        Specifies what is placed between array elements. Default is "" (empty string). ​

array ​ ​ ​ Required. Arrays to be combined into strings. ​

Technical details

Return value: ​ ​ ​ Returns a string composed of array elements.

PHP Version: 4+

<?php
$arr = array(&#39;Hello&#39;,&#39;World!&#39;,&#39;Beautiful&#39;,&#39;Day!&#39;);
echo implode(" ",$arr)."<br>";
echo implode("+",$arr)."<br>";
echo implode("-",$arr)."<br>"; 
echo implode("X",$arr);
?>

$SQL="delete from `doing` where id in ('1,2,3,4')";

<form action="?action=doing" method="post">
<input name="ID_Dele[]" type="checkbox" id="ID_Dele[]" value="1"/>
<input name="ID_Dele[]" type="checkbox" id="ID_Dele[]" value="2"/>
<input name="ID_Dele[]" type="checkbox" id="ID_Dele[]" value="3"/>
<input name="ID_Dele[]" type="checkbox" id="ID_Dele[]" value="4"/>
<input type="submit"/>
</form>

SQL="delete from [doing] where id in ('"&ID_Dele&"')". But PHP cannot put $ID_Dele directly into it. Because $ID_Dele is not '1,2,3,4', because $ID_Dele is an array with keys and values.
Okay, it’s not difficult in PHP. There happens to be a function: implode(), that’s right. A function that has the exact opposite function of split()\explode(). The latter two are separated by a certain character (such as a comma), while the former can be spliced ​​into a string.

Therefore:

$ID_Dele= implode(",",$_POST['ID_Dele']);$SQL="delete from `doing` where id in ($ID_Dele)";

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