array_slice and array_flip in php array functions

Look at array_slice first.

array_slice is used to take out a part of the array. There are two ways to use it:

$arr=array('a'=>'aa',
           'b'=>'bb',
           'c'=>'cc',
           'd'=>'dd');

//从数组中第1个数据(数组本身从0开始)开始,取两项。
$tmp=array_slice($arr,1,2);
showObj($tmp);
//从数组倒数第三个数据开始,往后取两项:
$tmp=array_slice($arr,-3,3);
showObj($tmp);

Next, look at the output result:

array(2) {
["b"]=>
string (2) "bb"
["c"]=>
string(2) "cc"
}

array(3) {
["b"]=>
string(2) "bb"
["c"]=>
string(2) "cc"
["d"]=>
string(2) "dd"
}

The showObj function is a package of var_dump, used to print specific Object.

function showObj($Obj)
{
  echo "<pre class="brush:php;toolbar:false">";
  var_dump($Obj);
  echo "

"; }
Let’s look at the array_flip function:

//array_flip用来交换数组中的键值对
$arr=array_flip($arr);
showObj($arr);

Output result:

array(4) {
["aa"]=>
string(1) "a"
["bb"]=>
string(1) "b"
["cc "]=>
string(1) "c"
["dd"]=>
string(1) "d"
}

The above introduces array_slice and array_flip in the PHP array function, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.