JavaScript 到 PHP 的转换

Question

我有一个 libphonenumber 包的 javascript 端口，它具有以下功能:

function cleanPhone(a){
    a=a.replace(/[^\d\+]/g,"");
    return a="+"==a.substr(0,1)?"+"+a.replace(/[^\d]/g,""):a.replace(/[^\d]/g,"")
}

我正在尝试将此函数转换为 PHP，并且想知道这是否正确:

function cleanPhone($a) {
    $a = preg_replace('/[^\d\+]/g',"", $a);
    return $a = "+" == substr(0,1)?"+"+ preg_replace('/[^\d]/g',"", $a) : preg_replace('/[^\d]/g',"", $a);
}

Answer 1

g is not a valid modifier in PCRE (the regex implementation PHP uses) because it's simply not needed; preg_replace() will perform global replacements by default. You'll find the modifier in true Perl regex as well as JavaScript regex, but not in PCRE.

我会写得更清楚:

function cleanPhone($a) {
    $a = preg_replace('/[^\d\+]/', "", $a);
    if(substr($a, 0, 1) == "+"){
       return "+" + preg_replace('/[^\d]/', "", $a); 
    }else{
      return preg_replace('/[^\d]/',"", $a);
    }
}

另请注意，您缺少 substring 方法的变量标识符 substr($string, $startIndex, [$length])

使用 ternary operator 的缩小版本也应该有效:

function cleanPhone($a) {
    $a = preg_replace('/[^\d\+]/',"", $a);
    return ("+" == substr($a,0,1))?"+"+ preg_replace('/[^\d]/',"", $a) : preg_replace('/[^\d]/',"", $a);
}