Comparison and analysis of function efficiency of splitting array elements_PHP tutorial

There is such a requirement. An array $data = array(12, 43, 87, 45) requires writing a custom function to separate the numbers of the array elements individually. The final array is as follows: $data = array(1, 2, 4, 3, 8, 7, 4, 5). It means to "split" all the numbers in the original array into "single" digits.

The following is a function I wrote:

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;
}

After testing it, it can still be executed. Call as follows:

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

The output result is:

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"
}

Although the execution is good, you will be surprised if you look at the standard answer. There is only one sentence in the function, as follows:

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

So I wrote a script to test the operating efficiency gap between my own and standard functions. There is a microtime_float() function in it to provide precise time support:

//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 - $mine_start) . " S 
";
echo "标准的函数调用运行时间为：" . (float)($sta_end - $sta_start) . " S 
";
$multiple = (int)((float)($mine_end - $mine_start) / (float)($sta_end - $sta_start));
echo "前者是后者的：" . $multiple . " 倍！";

Let’s take a look at the output:

自己的函数调用运行时间为：9.3936920166E-005 S 
标准的函数调用运行时间为：2.69412994385E-005 S 
前者是后者的：3 倍！ 

If you refresh the page multiple times, you can find that the execution efficiency of the standard function is basically 3 times that of your own function! Of course, the standard functions use PHP's built-in functions: str_split(), implode(), so it is much faster than writing the function yourself. Have no impression of the str_split() function? Let’s take a look at the manual explanation:

str_split -- Convert a string to an array (convert a string into an array)

Function description:

array str_split ( string string [, int split_length] )

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.

Example 1. Example uses of str_split()

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

Program execution result:

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
)

http://www.bkjia.com/PHPjc/752468.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/752468.htmlTechArticleThere is such a requirement, an array $data = array(12, 43, 87, 45), and it is required to write an Customize the function to separate the numbers of its array elements individually. The final array formed is as follows: $data =...