PHP array_merge function Features-one of the parameters is null

When I recently worked on a project, I needed to merge two arrays that were read from the database, so I thought of the Array_merge function in PHP, and the final result was always null, and by dump, it was discovered that one of the arrays was null. The demo is as follows:

$arr 1 =null;

$arr 2 = Array (' Tom ', ' linken ');

$arr 3 = Array_merge ($arr 1, $arr 2);

Var_dump ($arr 3);

The result of the run is null.

The solution is to force the type conversion of two parameters at the time of merge.

As follows:

$arr 1 =null;

$arr 2 = Array (' Tom ', ' linken ');

$arr 3 =array_merge ((array) $arr 1, (array) $arr 2);

Var_dump ($arr 3);

The result of the operation is:

Array (2) {[0]=> string (3) "Tom" [1]=> string (6) "Linken"}

The problem is resolved so that you do not have to determine whether $ARR1 and $ARR2 are null in your code.

The above describes the PHP real-array_merge function Features-one of the parameters is null, including the content, I hope to be interested in PHP tutorial friends helpful.

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