PHP array pointer operation implementation code

/**
* Rewind the array's internal pointer back to a
* @param array & $arr
* @return Mixed returns the value of the previous cell and returns FALSE when there are no more units
* If the array contains an empty cell, or if the value of the cell is 0, the function encounters these cells and returns FALSE
* To properly traverse an array that may contain empty cells or a cell value of 0, see the each () function
*/
Mixed prev (array & $arr);
<?php
$transport = Array (' foot ', ' bike ', ' car ', ' plane ');
$mode = current ($transport); $mode = ' foot ';
$mode = Next ($transport); $mode = ' bike ';
$mode = Next ($transport); $mode = ' car ';
$mode = prev ($transport); $mode = ' bike ';
$mode = End ($transport); $mode = ' plane ';
$mode = Reset ($transport);//$mode = ' foot ';
?>

Array ("Key" => "value");
Display array
Print_r ($array);
Use the compact () function to create a new array and make the argument a cell of the new array;
$newArray = Compact ("Red", "green", "yellow", "Blue", "array");
Use the Extract () function to convert a cell in an array to a variable
Extract ($exArray);
echo "$key 1 $key 2 $key 3 $key 4 $key 5";


※ Check value, key
Array_key_exists ($key, $array);//check array key
In_array ($value, $array);//check value to array

※ Get the value
Use Array_values () to get the value of an array
$carValues = Array_values ($car);
Remove the key name of the array
$twoKeys = Array_keys ($two);
Key ($array);//output keys for current cell
After the array is defined, use current () to get the value of the active cell
$red = current ($array);
List ($red, $green) = $array;//Assign the value in the array to the variable, $array = Array ("Red", "green");
each ($two);//returns the key and value of the current cell in the array

※ Traverse Array
foreach ($two as $subArray);//traversal array
while (the list ($key, $value) = each ($array)) {
echo "$key => $value,";//use each to traverse the array
}

※ Filled Array
Populate the array to the left and right
Array_pad ($array, +3, "Shuzhi");//2 parameter is padding from left to right and the value is larger than the number of cells
$array 1 = Array_fill (5,5, "test");//Use Array_fill () to populate the value of this array, the value is test, start with unit 5th, fill 5 cells
Fill Array Key Name
$keys = Array (' String ', 5, ' str ');
$array 3 = Array_fill_keys ($keys, "array value");
Exchanging key names and values using the ARRAY_FILP () function
$speed = Array_flip ($speed);
Use the Array_splice () function to replace the 6th cell with a value of 7
$output = Array_splice ($input, 6,0,7);
Delete an array cell using the Array_splice () function, leaving only the first 5 cells
$output = Array_splice ($input, 5);
$array 1 = range (10,100,10); Set the step value between cells using the third argument of the range () function


※ Sort
Shuffle ($array);//to disrupt array order
To sort three arrays using Array_multisort ()
Array_multisort ($sort 1, $sort 2, $sort 3);
Sort the array and keep the index relationship
Asort ($array);
Reverse-sort the test array and keep the index relationship
Arsort ($array);
Use Ksort () to sort the key names in the array
Ksort ($array);
Reverse sort using the Krsort () function key Name
Krsort ($array);
Sort the test array by using sort () [Arrange by Key name]
Sort ($array);
Use Natsort () sort [natural sort, in numerical order] for cell value case sensitivity
Natsort ($array);
Use the Natcasesort () function to sort [natural sort] but ignore numeric capitalization
Natcasesort ($array);
Use the Array_reverse () function to sort the array cells in the opposite order
$newArray = Array_reverse ($array, TRUE);//true preserve the original key name when set

※ Intersection, Difference set
Use Array_diff () to compute the difference set of three arrays [array numeric comparison]
$result = Array_diff ($dog 1, $dog 2, $dog 3);
Use ARRAY_DIFF_ASSOC () to compute the difference set for a three array [compare values and key names]
$result = Array_diff_assoc ($dog 1, $dog 2, $dog 3);
Use Array_diff_key () to compute the difference set of three arrays [compare key names]
$result = Array_diff_key ($dog 1, $dog 2, $dog 3);
Use Array_intersect () to compute the intersection of three arrays [array numeric comparisons]
$result = Array_intersect ($dog 1, $dog 2, $dog 3);
Use ARRAY_INTERSECT_ASSOC () to compute the intersection of three arrays [compare values and key names]
$result = Array_intersect_assoc ($dog 1, $dog 2, $dog 3);
Use Array_intersect_key () to compute the intersection of three arrays [compare key names]
$result = Array_intersect_key ($dog 1, $dog 2, $dog 3);

※ Merging arrays
Merging arrays using the Array_merge () function
$result = Array_merge ($array 1, $array 2, $array 3, $array 4, $array 5);
Array_rand ($input, 10);//randomly remove 10 units
Count ($array, count_recursive);//show number of array cells, 2 parameters can only be 1 or count_recursive, sometimes traversing multidimensional arrays

※ Access Stack
Array out of Stack, LIFO, the last cell of the array pops up
Array_pop ($array);
Array into the stack, adding 7, 82 values to the tail of the array
Array_push ($array, 7,8);
Move array start cell to group
Array_shift ($array);
Add 7, 8 to the beginning of the array
Array_unshift ($array, 7,8);