如何在多个位置使用substr_replace？

Question

我有一个电话号码，我想在字符串中添加2个空格，我使用substr_replace多次实现此目的。这是可能的一个用途。

$telephone = "07974621779"; 
$telephone1 = substr_replace($telephone, " ", 3, 0); 
$telephone2 = substr_replace($telephone1, " ", 8, 0); 

echo $telephone2; //outputs 079 7462 1779 

Answer 1

所有的这些都将做的工作：

$telephone = "07974621779"; 
$telephone=substr_replace(substr_replace($telephone," ",3,0)," ",8,0); 
// sorry still two function calls, but fewer lines and variables 
echo $telephone; //outputs 079 7462 1779 

echo "\n\n"; 

$telephone="07974621779"; 
$telephone=preg_replace('/(?<=^\d{3})(\d{4})/'," $1 ",$telephone); 
// this uses a capture group and is less efficient than the following pattern 
echo $telephone; //outputs 079 7462 1779 

$telephone="07974621779"; 
$telephone=preg_replace('/^\d{3}\K\d{4}/',' $0 ',$telephone); 
// \K restarts the fullstring match ($0) 
echo $telephone; //outputs 079 7462 1779 

Answer 2

可悲的是，你不能只是输入数组作为起始点和终止点是这样的：

$telephone1 = substr_replace($telephone, " ", array(3, 8), array(0, 0)); 

这意味着你可能需要编写您自己的包装函数：

function substr_replace_mul($string, $replacement, $start, $end) { 
    // probably do some error/sanity checks 
    for ($i = 0; $i < count($start); $i++) { 
     $string = substr_replace($string, $replacement, $start[$i], is_array($end) ? $end[$i] : $end); 
    } 

    return $string; 
} 

用法：

$telephone1 = substr_replace_mul($telephone, " ", array(3, 8), 0); 

Warni ng：写在浏览器中，完全未经测试，但我认为你明白了。