PHP Array traversal

<?php
/* Traversal of arrays
*
* 1. Iterating through an array using a For statement
* A. Other languages (only this way)
* B. This is not our preferred method in PHP
* C. The array must be an indexed array, and the subscript must also be contiguous
* (index array subscript can also be non-sequential, arrays and associative arrays)
*
*
* 2. Iterating through an array using a foreach statement
* foreach (array variable as variable value) {
*//Loop Body
* }
* A. The number of cycles is determined by the number of elements in the array
* B. Each iteration assigns the elements in the array to the following variables
*
* foreach (array variable as subscript variable = = value variable) {
*
* }
*
* 3. while () the list () each () combination loops through the array
*
* each () function,
* A. An array is required as a parameter
* B. Returned is also an array
* C. The returned array is 0, 1, key, value four subscript (fixed)
* 0 and key subscript are keys to the current parameter array element
* 1 and value subscript is the value of the current logarithmic array element
*
* d. The default is that the current element is the first element
* E. The current element is moved backwards after each execution
* F. Returns False if the function is executed again to the last element
*
*//array ([1] = 1 [value] = 1 [0] = = ID [key] + + ID)
*
* List () function

* A. List () =array (); You need to assign an array to this function
* B. The number of elements in the array to be the same as the number of parameters in the list () function
* C. Each element value in the array is assigned the value of each parameter in the list () function, and list () converts each argument to a variable
* d. List () can only receive indexed arrays
* E. Order of subscripts by index
*/
/*
$user =array ("id" =>1, "name" = "Zhangsan", "Age" =>10, "sex" = "Nan");

while ($arr =each ($user)) {
echo $arr [0]. " ==> ". $arr [1]." <br> ";
echo $arr ["Key"]. ----> ". $arr [" Value "]." <br> ";
}

Using the internal pointer control function of an array
Next (array);
Prev (array);
Reset (Array)
End (array);

Current (array);
Key (array);
*/

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