Implementation principle of javascript and php template engine

1. Simple replacement:

1. javascript:
   a. Code:

   var data = {
       'name':'lee',
       'place':'wuhan'
   }
   var str = "Hello {{name}}, Welcome to {{place}}!";
   var res = str.replace(
           /{{([\s\S]+?)}}/g,
           function(param1,param2){
               var index = param2
               return data[index]
           }
       );
   console.log(res)

   b. Output:

   Hello lee, Welcome to wuhan!

2. php:
   a. Code:

   <?php
   $data = array(
       'name'=>'lee',
       'place'=>'wuhan'
   );
   $str = "Hello {{name}}, Welcome to {{place}}!";
   $res = preg_replace_callback(
           "/{{([\s\S]+?)}}/",
           function($param) use($data){
               $index = $param[1];
               return $data[$index];
           },
           $str
       );
   echo $res;

   b. Output:

   Hello lee, Welcome to wuhan!

   Second, complex replacement:

3. javascript:
   a. Code:

   var data = {
   'name':'lee',
   'place':'wuhan'
   }
   var str = "Hello {{data.name}}, Welcome to {{data.place}}!";
   var res = str.replace(
       /{{([\s\S]+?)}}/g,
       function(param1,param2){
           var ret = eval(param2)
           return ret
       }
   );
   console.log(res)

   b. Output:

   Hello lee, Welcome to wuhan!

4. php:
   a. Code:

   <?php
   $data = array(
       'name'=>'lee',
       'place'=>'wuhan'
   );
   $str = "Hello {{data.name}}, Welcome to {{data.place}}!";
   $res = preg_replace_callback(
           "/{{([\s\S]+?)}}/",
           function($param) use($data){
               $raw = $param[1];
               $arr = explode('.',$raw);
               $command = 'return '.'$'.$arr[0].'[\''.$arr[1].'\'];';
               $ret = eval($command);
               return $ret;
           },
           $str
       );
   echo $res;

   b. Output:

   Hello lee, Welcome to wuhan!