在 javascripts 和 php 中连接数字

Question

I translate some code from javascript to php, my problem is with numbers, because in javascript "+" is used in both situation, addition and concatenating. ex:

1+1+ "2" +"4"+3 - 5 -1+"" + 2 

in javascript result is 22372

How can I make this in php? I try with preg_replace

1+1 --> 2
2+"2" --> "22" // as string
""+2 --> "2" 

problem is here:

(1+1+ "2" +"4"+3 - 5 -1)+""+2

I need to solve () then concatenating with "" and 2

Answer 1

String concatenation is done with "." rather than "+" in php. You can still concatenate values of different types, eg

$apple_count = 25;
$my_string = "I want " . $apple_count . " apples.";

Answer 2

I work on a solution

echo $a." = 22372"."\n";
function concat_num($a) {
 while (preg_match("/\"(\d+)\"\s*\+\s*(\d+)/",$a) || preg_match("/^(?!\-)\s*(\d+)\s*\+\s*\"(\d+)\"/",$a)) { // "10" + 2 or 2 + "10"
 while (preg_match("/(\d+)\s*\+\s*(\d+)/",$a)) {    //1 + 2 --> 3
  $a=preg_replace_callback(
    "/(\d+)\s*\+\s*(\d+)/",
    function ($m) {
      return floor($m[1]+$m[2]);
    },
    $a
    );
 }
 echo $a."\n";
 while (preg_match("/\"\"\s*\+\s*(\d+)/",$a)) {
  $a=preg_replace("/\"\"\s*\+\s*(\d+)/",'"'."\$1".'"',$a);  // ""+11   ---> "11"
 }
 echo $a."\n";
 while (preg_match("/(\d+)\s*\+\s*\"\"/",$a)) {
  $a=preg_replace("/(\d+)\s*\+\s*\"\"/",'"'."\$1".'"',$a);  // 11+""   ---> "11"
 }
 echo $a."\n";
 while (preg_match("/\"(\d+)\"\s*\+\s*\"\"/",$a)) {
  $a=preg_replace("/\"(\d+)\"\s*\+\s*\"\"/",'"'."\$1".'"',$a); // "11"+"" --> "11"
 }
 echo $a."\n";
 while (preg_match("/\"\"\s*\+\s*\"(\d+)\"/",$a)) {
  $a=preg_replace("/\"\"\s*\+\s*\"(\d+)\"/",'"'."\$1".'"',$a);  // ""+"22" -->"22"
 }
 echo $a."\n";
 while (preg_match("/\"(\d+)\"\s*\+\s*\"(\d+)\"/",$a)) {
  $a=preg_replace("/\"(\d+)\"\s*\+\s*\"(\d+)\"/",'"'."\$1\$2".'"',$a); // "11"+"22" --> "1122"
 }
 echo $a."\n";
 while (preg_match("/\"(\d+)\"\s*\+\s*(\d+)/",$a)) {
  $a=preg_replace("/\"(\d+)\"\s*\+\s*(\d+)/",'"'."\$1\$2".'"',$a); // "11"+22 -->> "1122"
 }
 echo $a."\n";
 while (preg_match("/^(?!\-)\s*(\d+)\s*\+\s*\"(\d+)\"/",$a,$m)) {
 $a=preg_replace("/^(?!\-)\s*(\d+)\s*\+\s*\"(\d+)\"/",'"'."\$1\$2".'"',$a); // 11+"22" --->> "1122"
 }
 echo $a."\n";
 while (preg_match("/\"(\d+)\"\s*\-\s*(\d+)/",$a)) {  // "10" - 8 --> 2
  $a=preg_replace_callback(
    "/\"(\d+)\"\s*\-\s*(\d+)/",
    function ($m) {
      return floor($m[1]-$m[2]);
    },
    $a
  );
 }
 echo $a."\n";
 while (preg_match("/(\d+)\s*\-\s*(\d+)/",$a)) {    //5 - 2 --> 3
  $a=preg_replace_callback(
    "/(\d+)\s*\-\s*(\d+)/",
    function ($m) {
      return floor($m[1]-$m[2]);
    },
    $a
    );
 }
 echo $a."\n";
 }
 return $a;
}
echo $b=concat_num($a)."\n";
$code="\$d=".$b.";";
eval ($code);
echo $d."\n";

And result

1+1+ "2" +"4"+3 - 5 -1+"" + 2 = 22372
2+ "2" +"4"+3 - 5 -1+"" + 2
2+ "2" +"4"+3 - 5 -1+"2"
2+ "2" +"4"+3 - 5 -1+"2"
2+ "2" +"4"+3 - 5 -1+"2"
2+ "2" +"4"+3 - 5 -1+"2"
2+ "24"+3 - 5 -1+"2"
2+ "243" - 5 -1+"2"
"2243" - 5 -1+"2"
2238 -1+"2"
2237+"2"
2237+"2"
2237+"2"
2237+"2"
2237+"2"
2237+"2"
2237+"2"
2237+"2"
"22372"
"22372"
"22372"
"22372"
22372

This seems to work but the best solution is to evaluate string from beginning to end.

1+1 --> 2 (num)
2+"2" --> "22" (string)
"22"+"4" --> "224" (string)
"224"+3 --> "2243" (string)
2243-5 --> 2238 (num)
2238-1 --> 2237 (num)
2237+"" --> "2237" (string)
"2237"+"2" --> "22372" (string)