How to find the median of a large array in php

Method: 1. Use sort() to sort the array, and use count() to find the length of the array; 2. Use "length%2==0" to determine whether the length is an even number or an odd number, and if it is an even number, the median It is "(array name [(length)/2] array name [((length)/2) 1])/2", otherwise it is "array [(length/2)-0.5".

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

php seeks a large array Median method

Implementation idea:

• Use sort() to sort the array, Then use count() to find the length of the array

• Determine whether the length of the array is even or odd

  If the length of the array is even, then the median will bearr[ Array length/2] arr[(array length/2) 1]/ 2.

  If the array length is odd, the median will be the middle elementarr[(array length / 2) - 0.5].

Implementation code:

"; }else{ // 如果长度是奇数 echo "中位数为： ".($arr[($len/2)-0.5])."
"; } } $arr1=[1, 4, 7, 9]; f($arr1); $arr2=[1, 2, 4, 7, 9]; f($arr2); ?>

Recommended learning: "PHP video tutorial》

The above is the detailed content of How to find the median of a large array in php. For more information, please follow other related articles on the PHP Chinese website!