PHP merges the array + number and the difference between array_merge, array array_merge

PHP merges the array + number and the difference between array_merge, array array_merge

There are two methods for PHP array Fusion: one is to directly add the plus sign, and the other is to use the array_merge function to add the two. There is a difference between the two:

1. The addition indicates that the natural index in the array is not reset.
2. In the addition method, the values in the added array are not overwritten.
3. The natural index in the merge function will be reset.
4. the merge function is unrelated to the relationship between merge and merge. The value of the array parameter after the merge function overwrites the value of the same key as the previous array parameter.

Example:

Array 1:

$arr1 = array(  10 => 'valueof10',  11 => 'valueof11',  'key1' => 'dataofkey1',  'key2' => 'dataofkey2',  'array' => array(    'key1' => 1,    'key2' => 'abc',    'key3' => array(      1, 2, 'name' => 'peter'    ),  ),);

Array 2:

$arr2 = array(  10 => 'newvalueof10',  11 => 'newvalueof11',  'key1' => 'newdataofkey1',  'key3' => 'newdataofkey3',  'array' => array(    'key1' => 2,    'key2' => 'defg',    'key3' => array(      1, 2, 'name' => 'jonathan', 'gender' => 'male'    ),  ),);

Result comparison:

array (size=6) 10 => string 'valueof10' (length=9) 11 => string 'valueof11' (length=9) 'key1' => string 'dataofkey1' (length=10) 'key2' => string 'dataofkey2' (length=10) 'array' =>   array (size=3)   'key1' => int 1   'key2' => string 'abc' (length=3)   'key3' =>     array (size=3)     0 => int 1     1 => int 2     'name' => string 'peter' (length=5) 'key3' => string 'newdataofkey3' (length=13) array (size=8) 0 => string 'valueof10' (length=9) 1 => string 'valueof11' (length=9) 'key1' => string 'newdataofkey1' (length=13) 'key2' => string 'dataofkey2' (length=10) 'array' =>   array (size=3)   'key1' => int 2   'key2' => string 'defg' (length=4)   'key3' =>     array (size=4)     0 => int 1     1 => int 2     'name' => string 'jonathan' (length=8)     'gender' => string 'male' (length=4) 2 => string 'newvalueof10' (length=12) 3 => string 'newvalueof11' (length=12) 'key3' => string 'newdataofkey3' (length=13)