PHP 函数执行效率的小比较

function splitStrToArray_mine($array)
{
$new_array = array();
foreach($array as $value)
{
$value = (string)$value;
$len = strlen($value);
for($i = 0; $i < $len; $i ++){
array_push($new_array, $value{$i});
}
}
return $new_array;
}

//测试数组
$data = array(12, 43, 87, 45, 98, 74, 83, 67, 12);
var_dump(splitStrToArray_mine($data));

array(18) {
[0]=>
string(1) "1"
[1]=>
string(1) "2"
[2]=>
string(1) "4"
[3]=>
string(1) "3"
[4]=>
string(1) "8"
[5]=>
string(1) "7"
[6]=>
string(1) "4"
[7]=>
string(1) "5"
[8]=>
string(1) "9"
[9]=>
string(1) "8"
[10]=>
string(1) "7"
[11]=>
string(1) "4"
[12]=>
string(1) "8"
[13]=>
string(1) "3"
[14]=>
string(1) "6"
[15]=>
string(1) "7"
[16]=>
string(1) "1"
[17]=>
string(1) "2"
}

//标准函数
function splitStrToArray($array)
{
return str_split(implode("", $array));
}

//测量时间的函数
function microtime_float()
{
list($usec, $sec) = explode(" ", microtime());
return ((float)$usec + (float)$sec);
}
//自定义函数
function splitStrToArray_mine($array)
{
$new_array = array();
foreach($array as $value)
{
$value = (string)$value;
$len = strlen($value);
for($i = 0; $i < $len; $i ++){
array_push($new_array, $value{$i});
}
}
return $new_array;
}
//标准函数
function splitStrToArray($array)
{
return str_split(implode("", $array));
}
//测试数组
$data = array(12, 43, 87, 45, 98, 74, 83, 67, 12);
//开始测试
$mine_start = microtime_float();
splitStrToArray_mine($data);
$mine_end = microtime_float();
//标准函数调用
$sta_start = microtime_float();
splitStrToArray($data);
$sta_end = microtime_float();
echo "自己的函数调用运行时间为：" . (float)($mine_end - $mine_start) . " S <br />";
echo "标准的函数调用运行时间为：" . (float)($sta_end - $sta_start) . " S <br />";
$multiple = (int)((float)($mine_end - $mine_start) / (float)($sta_end - $sta_start));
echo "前者是后者的：" . $multiple . " 倍！";

Converts a string to an array. If the optional split_length parameter is specified, the returned array will be broken down into chunks with each being split_length in length, otherwise each chunk will be one character in length.
FALSE is returned if split_length is less than 1. If the split_length length exceeds the length of string, the entire string is returned as the first (and only) array element.

<?php
$str = "Hello Friend";
$arr1 = str_split($str);
$arr2 = str_split($str, 3);
print_r($arr1);
print_r($arr2);
?>

Array
(
[0] => H
[1] => e
[2] => l
[3] => l
[4] => o
[5] =>
[6] => F
[7] => r
[8] => i
[9] => e
[10] => n
[11] => d
)
Array
(
[0] => Hel
[1] => lo
[2] => Fri
[3] => end
)