PHP把下划线分隔命名的字符串与驼峰式命名互转

<?php
//微妙时间
function microtime_float()
{
    list($usec, $sec) = explode(" ", microtime());
    return ((float)$usec + (float)$sec);
}

//将下划线命名转换为驼峰式命名
function convertUnderline1 ( $str , $ucfirst = true)
{
    while(($pos = strpos($str , ‘_‘))!==false)
        $str = substr($str , 0 , $pos).ucfirst(substr($str , $pos+1));

    return $ucfirst ? ucfirst($str) : $str;
}

//将下划线命名转换为驼峰式命名
function convertUnderline2 ( $str , $ucfirst = true)
{
    $str = explode(‘_‘ , $str);
    foreach($str as $key=>$val)
        $str[$key] = ucfirst($val);

    if(!$ucfirst)
        $str[0] = strtolower($str[0]);

    return implode(‘‘ , $str);
}

//将下划线命名转换为驼峰式命名
function convertUnderline3 ( $str , $ucfirst = true)
{
    $str = ucwords(str_replace(‘_‘, ‘ ‘, $str));
    $str = str_replace(‘ ‘,‘‘,lcfirst($str));
     return $ucfirst ? ucfirst($str) : $str;
}

//将下划线命名转换为驼峰式命名
function convertUnderline4 ( $str , $ucfirst = true)
{
    $str = preg_replace(‘/_([A-Za-z])/e‘,"strtoupper(‘$1‘)",$str);
    return $ucfirst ? ucfirst($str) : $str;
}

//将下划线命名转换为驼峰式命名
function convertUnderline5 ( $str , $ucfirst = true)
{
    $str = preg_replace_callback(‘/([-_]+([a-z]{1}))/i‘,function($matches){
        return strtoupper($matches[2]);
    },$str);
    return $ucfirst ? ucfirst($str) : $str;
}

$counts = 100000;
//第1种方式调用10w次所需时间
$s1 = microtime_float();
for ($i=0;$i<$counts;$i++)
{
    $str= ‘abcd_efgh_igk_lmn‘;
    convertUnderline1($str);
}
$e1 = microtime_float();
echo ‘convertUnderline1: run time = ‘;
echo $e1-$s1;echo ‘<br />‘;

//第2种方式调用10w次所需时间
$s2 = microtime_float();
for ($i=0;$i<$counts;$i++)
{
    $str= ‘abcd_efgh_igk_lmn‘;
    convertUnderline2($str);
}
$e2 = microtime_float();
echo ‘convertUnderline2: run time = ‘;
echo $e2-$s2;echo ‘<br />‘;

//第3种方式调用10w次所需时间
$s2 = microtime_float();
for ($i=0;$i<$counts;$i++)
{
    $str= ‘abcd_efgh_igk_lmn‘;
    convertUnderline3($str);
}
$e2 = microtime_float();
echo ‘convertUnderline3: run time = ‘;
echo $e2-$s2;echo ‘<br />‘;

//第4种方式调用10w次所需时间
$s2 = microtime_float();
for ($i=0;$i<$counts;$i++)
{
    $str= ‘abcd_efgh_igk_lmn‘;
    convertUnderline4($str);
}
$e2 = microtime_float();
echo ‘convertUnderline4: run time = ‘;
echo $e2-$s2;echo ‘<br />‘;

//第5种方式调用10w次所需时间
$s2 = microtime_float();
for ($i=0;$i<$counts;$i++)
{
    $str= ‘abcd_efgh_igk_lmn‘;
    convertUnderline4($str);
}
$e2 = microtime_float();
echo ‘convertUnderline5: run time = ‘;
echo $e2-$s2;echo ‘<br />‘;