Detailed explanation of PHP sorting algorithm examples

This article mainly introduces the PHP sorting algorithm, and analyzes the related operating skills and precautions of PHP data query, sorting, array deduplication, traversal and sorting in the form of examples. Friends in need can refer to the following

Use PHP to write sorting. Although PHP automatically automates many sorting methods, SQL statements can also quickly read data in order from the database. But different needs still require flexible application of the basic knowledge of PHP learned.

I want to achieve the following effect

Sorting algorithm effect diagram

It is to sort all the data in a value by time and divide it into rows Display the

<?php
  $array = $mysql->query_array($mysql->sql_select("user","userid,truename,year"," ")); //从数据库里面读出数据
  $year = array(); //设置空数组
  foreach($array as $value)
  {
    array_push($year,$value[2]); //把数据数组里面的时间数据入栈
  }
  $year = array_unique($year); //去除数组中重复的数据
  usort($year, "strnatcmp"); //将数组中的数据按自然数排序
  $num = count($year); //统计数据中数据的个数
 /*处理函数*/
 function isyear($value,$array)
 {
   $user = array(); //建立空数组
   foreach($array as $val)
   {
    if($val[2] == $value)
    {
     array_push($user,$val);
    }
   }
   return $user; //返回数组
 }
?>

above word processing function. The following is the display part of the code

<?php
for($i=0;$i<$num;$i++)
{
echo "<p class=&#39;box_user&#39;>";
echo "<p class=&#39;boxleft&#39;>{$year[$i]}届</p>";
echo  "<p class=&#39;boxright&#39;>";
$user = isyear($year[$i],$array);
foreach($user as $v)
{
echo "<span class={$v[0]}>{$v[1]}</span>";
}
echo "</p>";
echo "</p>";
}
?>

The data display code should be easy to understand, so I will not write comments line by line here.

This way we can get the effect we need to start with. Don't think that's the end of it. . This is just a first step idea, abstracting the actual problem into code. I don’t know what the effect will be?

We can use timestamps to calculate the time it takes to load page data and use PHP automatic functions.

<?php
  memory_get_usage();
?>

To calculate the memory occupied by the code while it is running.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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