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Let’s now analyze how to merge two arrays and merge elements with the same key value together during the PHP development process.
Example 1
The simplest merge method
$a = [ 1=>'a', 2=>'b', 3=>'c' ]; $b = [ 3=>'e', 4=>'f', 5=>'c' ]; $c = $a+$b; print_r($c);
Output:
Array ( [1] => a [2] => b [3] => c [4] => f [5] => c )
Analysis:$ a[3]
covers $b[3]
. When there are elements with the same key value in the array, the previous array will be followed by the array elements with the same key value
Example 2
Using foreach loop assignment method
$a = [ 1=>'a', 2=>'b', 3=>'c' ]; $b = [ 3=>'e', 4=>'f', 5=>'a' ]; foreach ($b as $key => $val) { $a[$key] = $val; } print_r($a);
Output:
Array ( [1] => a [2] => b [3] => e [4] => f [5] => a )
Analysis: A little different from Example 1
Array used for looping $b
will overwrite the elements of the array $a
, and only overwrite elements with the same key value
Related functions:
array_merge
array_intersect
##array_intersect_ukey
array_intersect_uassoc
array_intersect_key
##Related learning recommendations:
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