Method of merging arrays in php. php calls class method. php calls parent class method. Getting started with php learning.

There are two ways to merge arrays in php. Let me explain the specific method slowly:

1. The array_merge() function merges arrays
The specific example is as follows:

<code><span><span><?php</span><span>$a</span> = <span>array</span>( 
    <span>'where'</span> => <span>'uid=1'</span>, 
    <span>'order'</span> => <span>'uid'</span>, 
    <span>'limit'</span> => <span>'5'</span>
); 
<span>$b</span> = <span>array</span>( 
    <span>'where'</span> => <span>'uid=2'</span>, 
    <span>'order'</span> => <span>'uid desc'</span>, 
); 

<span>$c</span> = array_merge(<span>$a</span>,<span>$b</span>);
print_r(<span>$c</span>);

<span>$d</span> = array_merge(<span>$b</span>,<span>$a</span>);
print_r(<span>$d</span>);</span></span></code>

The output result is as follows:

Array ( [where] => uid=2 [order] => uid desc [limit] => 5 )
Array ( [where] => uid=1 [order] => uid [limit] => 5 )

Pay attention to the where and uid fields, these two fields are the $a and $b arrays Common fields in China, what can be concluded by paying attention to the difference between the values ​​of these two fields in the results?
When merging arrays using array_merge, if there are duplicate keys, the key value is the same as the key value of the field in the second parameter of the function.
2. Operator + merge array
Specific examples are as follows:

<code><span><span><?php</span><span>$a</span> = <span>array</span>( 
    <span>'where'</span> => <span>'uid=1'</span>, 
    <span>'order'</span> => <span>'uid'</span>, 
    <span>'limit'</span> => <span>'5'</span>
); 
<span>$b</span> = <span>array</span>( 
    <span>'where'</span> => <span>'uid=2'</span>, 
    <span>'order'</span> => <span>'uid desc'</span>, 
); 

<span>$c</span> = <span>$a</span>+<span>$b</span>;
print_r(<span>$c</span>);

<span>$d</span> = <span>$b</span>+<span>$a</span>;
print_r(<span>$d</span>);</span></span></code>

The output result is as follows:

Array ( [where] => uid=1 [order] => uid [limit] => 5 )
Array ( [where] => uid=2 [order] => uid desc [limit] => 5 )

As above, we still pay attention to the values ​​​​of the where and order fields. What conclusions can we draw?
When merging arrays using operator+, the key value of a duplicate key is the same as the value in the frontmost array with that key
Summary: There are two ways to merge arrays in PHP. One is to use PHP's own function array_merge, and the other is to use operator +. The difference is that when the arrays that need to be merged have the same key value, array_merge merges the key. The key value of is the same as the key value of the key in the latter, that is, it will be overwritten; when the operator + sign is used, the key value of the key is the same as the key value of the key in the former, that is, the correlation will not be executed when encountering an existing key value. action.
The above are the similarities and differences between the two methods of merging arrays in PHP. Thank you for reading. ').addClass('pre-numbering').hide(); $(this).addClass('has-numbering').parent().append($numbering); for (i = 1; i ').text(i)); }; $numbering.fadeIn(1700); }); });

The above introduces the method of merging arrays in PHP, including the methods of PHP. I hope it will be helpful to friends who are interested in PHP tutorials.