A detailed explanation of the foreach usage in PHP

What is 1.foreach?

foreach is a grammatical structure of PHP, is actually a tool, (tool: Is the work of the use of the appliance), then in the program development process, in order to achieve the program effect, the use of foreach.

2. How to use?

Official:

foreach (array_expression as $value)    statement foreach (array_expression as $key = $value)  statement　　
Example 1:
　　

    $arr = Array (1,2,3,4);//define Array    foreach ($arr as & $value) {    $value = $value *2;//loop through and modify the values in the array    }    echo "<pre>";    Print_r ($arr);//Print out the final result

Result: (& $value is reference assignment)

Array (    [0] = 2  [1] = 4   [2] = 6   [3] = 8)　　
Example 2:
　　

            $a = Array (    "one" = 1, "One" =    2,    "three" = 3,    "Seventeen"); foreach ($a as $k =&G T $v) {echo "<pre>";    echo "[$k] = $v \ n";}    

Results:

　　　　

[One] = 1

[2] + =

[Three] = 3

[Seventeen] = 17

Explanation: K actually refers to is key,v actually refers to is the value

Summary: foreach is used frequently in PHP projects, especially when working with arrays!
May 10, 2017 18:36:25 in Beijing

A detailed explanation of the foreach usage in PHP