Various methods of sorting arrays in php_PHP tutorial-PHP Tutorial-php.cn

Various methods of sorting arrays in php_PHP tutorial

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Release： 2016-07-13 16:55:55

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When we learn programming, we know that sorting methods include bubble sorting, quick sorting, selection sorting, etc., and the simultaneous sorting method Divided into two categories internal and external.

Sort method of array
Divided into two categories:
1. Internal (memory) sorting
2. External sorting (the amount of data is too large to be stored in the memory, so external sorting is required
Storage)

----------------
Sorting is a basic skill for a programmer
1: Internal sorting
(1) Commutative sorting
1. Bubble method

The default transfer of arrays is value transfer, not address transfer
We will talk about object types later. The default transfer of objects is address transfer

//Optimize, encapsulate the bubble sorting method into a function to facilitate future use

$myarr[$j]= $myarr[$j+1];

The code is as follows

代码如下

复制代码

function bubbleSort(&$myarr){
$temp=0;//定义一个中间变量
//外层循环
for($i=0;$i for($j=0;$j $j++){
if($myarr[$j]>$myarr[$j
+1]){
$temp=$myarr[$j];
$myarr[$j]=
$myarr[$j+1];
$myarr[$j+1]=
$temp;
}

}
}
}

$arry=array(2,6,-4,7,9,0);
bubbleSort($arry);
print_r($arry);

Copy code

function bubbleSort(&$myarr){

$temp=0;//Define an intermediate variable

代码如下

复制代码

function selectSort(&$myarr){
$temp=0;
for($i=0;$i //假设$i就是最小的数
$minval=$myarr[$i];
//记录我认为的最小数的下标
$minIndex=$i;

for($j=$i+1;$j +){
//说明我们认为的最小值，不是最小
if($minval>$myarr[$j]){

$minval=$myarr[$j];
$minIndex=$j;

}

}
//最后交换
$temp=$myarr[$i];
$myarr[$i]=$myarr[$minIndex];
$myarr[$minIndex]=$temp;
}