Efficiency comparison of several string connections in PHP
php has roughly three types of string connections:
#1. Directly use . to connect.
2. Use .= to connect.
3. First push into the array, and then connect through the join function.
The efficiency of these three methods are tested below:
The code of the first method is as follows:
<?php
function get_tm() {
list ( $usec, $sec ) = explode ( " ", microtime () );
return (( float ) $usec + ( float ) $sec);
}
$temp="test";
$result="";
define("num",100000);
$start=get_tm();
for($i=0;$i<num;$i++)
{
$result=$result.$temp;
}
echo get_tm()-$start;
?>Run 4 times, excluding the first running time, the three times are:
22.165272951126
22.003527164459
22.15947508812
The code for the second method is as follows:
<?php
function get_tm() {
list ( $usec, $sec ) = explode ( " ", microtime () );
return (( float ) $usec + ( float ) $sec);
}
$temp="test";
$result="";
define("num",100000);
$start=get_tm();
for($i=0;$i<num;$i++)
{
$result.=$temp;
}
echo get_tm()-$start;
?>Run 4 times, excluding the first running time , the three times are:
3.1967310905457
3.1296961307526
3.0872850418091
##The third method code is as follows:
<?php
function get_tm() {
list ( $usec, $sec ) = explode ( " ", microtime () );
return (( float ) $usec + ( float ) $sec);
}
$temp="test";
$result="";
$arr=array();
define("num",100000);
$start=get_tm();
for($i=0;$i<num;$i++)
{
array_push($arr, $temp);
}
$result=join($arr);
echo get_tm()-$start;
?>3.2759411334991
3.2663381099701
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