The PHP array is actually an ordered map. A mapping to values associated keys type. This type is optimized in many ways, so you can use it as a real array, or list (vector), hash table (an implementation is mapped), dictionary, collection, stack, queue and probably more. Since the array element can also be another array, multi-dimensional arrays, and the tree structure are allowed.
Types of
- Indexed array, from array from 0,1
- Associative array, i.e. custom key
Reconstruction
array_column(arr,key,index);
In the key pass NUll, which can rebuild a new array is an indexed array
$a = array( 'a' => 'baidu', 'b' => 'qq', 'c' => 'nho', ); print_r(array_column($a,null)); //echo array('baidu','qq','nho')
array_merge($arr1,$arr2);
Method can be used not only key index of the array starts at 0, to the associated index is not valid, only passing a current index of the array, it will be the current array index rebuild
$b = [ 1=>'baidu', '1123', 'nho', ]; print_r(array_merge($b)); //echo array('baidu','1123','nho')
array_splice($arr,$start,$length,$replacement);
This method returns the specified segment array, $ replacement will be set to true numerical index rebuild
$b = array( '1' => 'baidu', '2' => 'qq', '3' => 'nho', '4' => 'vv' ); $count = count($b); print_r(array_splice($b,0,$count,true)); //echo array('baidu','qq','nho','vv')