Comparison of two usages of PHP's foreach()_PHP Tutorial

There are two ways to use PHP’s foreach():

The first way to use PHP’s foreach():

<ol class="dp-xml">
<li class="alt"><span><span>foreach(array_nameas$value)  </span></span></li>
<li class=""><span>{  </span></li>
<li class="alt"><span>statement;  </span></li>
<li class=""><span>}  </span></li>
</ol>

The array_name here is the name of the array you want to traverse. In each loop, the value of the current element of the array_name array is assigned to $value, And the subscript inside the array moves down one step, that is, the next loop will return to get the next element.

The second usage of PHP's foreach():

<ol class="dp-xml">
<li class="alt"><span><span>foreach(array_nameas$</span><span class="attribute"><font color="#ff0000">key</font></span><span>=</span><span class="tag"><strong><font color="#006699">></font></strong></span><span>$value)  </span></span></li>
<li class=""><span>{  </span></li>
<li class="alt"><span>statement;  </span></li>
<li class=""><span>}  </span></li>
</ol>

The difference between PHP's foreach() here and the first method is that there is an extra $key, that is, in addition to In addition to the value of the current element being assigned to $value, the key value of the current element will also be assigned to the variable $key in each loop. The key value can be a subscript value or a string. For example, "0" in book[0]=1, "id" in book[id]="001".

http://www.bkjia.com/PHPjc/446434.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/446434.htmlTechArticlePHP’s foreach() has two usages: PHP’s foreach() first usage: foreach(array_nameas$ value) { statement; } The array_name here is the name of the array you want to traverse. In each loop, ar...