Use foreach in php to operate the array code

Foreach () has two usage methods:
Copy codeThe Code is as follows:
Foreach (array_name as $ value)
{
Statement;
}

Here, array_name is the name of the array to be traversed. In each loop, the value of the current element of the array_name array is assigned to $ value, and the downloading inside the array moves down one step, that is, the next element is returned in the next loop.
Copy codeThe Code is as follows:
Foreach (array_name as $ key => $ value)
{
Statement;
}

The difference between this method and the first method is that there is an extra $ key, that is, in addition to assigning the value of the current element to $ value, the key value of the current element is also assigned to the variable $ key in each loop. The key value can be either a lower mark value or a string. For example, "0" in book [0] = 1, "id" in book [id] = "001 ".
Program instance 1:
Copy codeThe Code is as follows:
<? Php
/*-------------------------------------------------------------------------*/
/* Foreach example 1: value only */
Echo "foreach example 1: value only". '<br/> ';
$ A = array (1, 2, 3, 17 );
Foreach ($ a as $ v ){
Echo "Current value of". $ a. ":". $ v. "<br/> ";
}
?>
// Running result
Foreach example 1: value only
Current value of $ a: 1
Current value of $ a: 2
Current value of $ a: 3
Current value of $ a: 17

2
Copy codeThe Code is as follows:
/*-------------------------------------------------------------------------*/
/* Foreach example 2: value (with key printed for authentication )*/
Echo '<br/>'. '<br/>'. "foreach example 2: value (with key printed for authentication)". '<br/> ';
$ A = array (1, 2, 3, 17 );
$ I = 0;/* for each strative purposes only */
Foreach ($ a as $ v ){
Echo "" $ a [$ I] => $ v ". '<br/> ';
$ I ++;
}
// Program running result
Foreach example 2: value (with key printed for authentication)
$ A [0] => 1
$ A [1] => 2
$ A [2] => 3
$ A [3] => 17

3
Copy codeThe Code is as follows:
/*-------------------------------------------------------------------------*/
/* Foreach example 3: key and value */
Echo '<br/>'. '<br/>'. "foreach example 3: key and value". '<br/> ';
$ A = array (
"One" => 1,
"Two" => 2,
"Three" => 3,
"Seventeen" => 17
);
Foreach ($ a as $ k => $ v ){
Echo "" $ a [$ k] => $ v ". '<br/> ';
}
// Program running result
Foreach example 3: key and value
$ A [one] => 1
$ A [two] => 2
$ A [three] => 3
$ A [seventeen] => 17

4
Copy codeThe Code is as follows:
/*-------------------------------------------------------------------------*/
/* Foreach example 4: multi-dimen1_arrays */
Echo '<br/>'. '<br/>'. "foreach example 4: multi-dimen1_arrays". '<br/> ';
$ A = array ();
$ A [0] [0] = "";
$ A [0] [1] = "B ";
$ A [1] [0] = "y ";
$ A [1] [1] = "z ";
Foreach ($ a as $ v1 ){
Foreach ($ v1 as $ v2 ){
Echo "$ v2" n ";
}
}
// Program running result
Foreach example 4: multi-dimen1_arrays
A B y z

5
Copy codeThe Code is as follows:
/*-------------------------------------------------------------------------*/
/* Foreach example 5: dynamic arrays */
Echo '<br/>'. '<br/>'. "foreach example 5: dynamic arrays". '<br/> ';
Foreach (array (1, 2, 3, 4, 5) as $ v ){
Echo "$ v" n ";
}
// Program running result
Foreach example 5: dynamic arrays
1 2 3 4 5

This can also be used:
Copy codeThe Code is as follows:
$ MessageNav ['homepage'] = ROOT_PATH;
$ MessageNav ['talent communication'] = "#"
$ MessageNav ['dynamic column'] = "hragent/cn /"
<? Php $ I = 0; foreach ($ messageNav as $ key => $ value):?>
<? Php if ($ I! = Count ($ messageNav)-1):?>
<A href = "<? = $ Value?> "> <? = $ Key?> </A>
<? Php else:?>
<A href = "<? = $ Value?> "Class =" onlink "> <? = $ Key?> </A>
<? Php endif;?>
<? Php $ I ++; endforeach;?>