PHP中数组转换成json字符串程序代码

function array_to_json($array) {
 if (! is_array ( $array )) {
  return false;
 }
 
 $associative = count ( array_diff ( array_keys ( $array ), array_keys ( array_keys ( $array ) ) ) );
 if ($associative) {
 
  $construct = array ();
  foreach ( $array as $key => $value ) {
  
   // We first copy each key/value pair into a staging array,
   // formatting each key and value properly as we go.
  

   // Format the key:
   if (is_numeric ( $key )) {
    $key = "key_$key";
   }
   $key = """ . addslashes ( $key ) . """;
  
   // Format the value:
   if (is_array ( $value )) {
    $value = array_to_json ( $value );
   } else if (! is_numeric ( $value ) || is_string ( $value )) {
    $value = """ . addslashes ( $value ) . """;
   }
  
   // Add to staging array:
   $construct [] = "$key: $value";
  }
 
  // Then we collapse the staging array into the JSON form:
  $result = "{" . implode ( ",", $construct ) . "}";
 
 } else { // If the array is a vector (not associative):
 

  $construct = array ();
  foreach ( $array as $value ) {
  
   // Format the value:
   if (is_array ( $value )) {
    $value = array_to_json ( $value );
   } else if (! is_numeric ( $value ) || is_string ( $value )) {
    $value = """ . addslashes ( $value ) . """;
   }
  
   // Add to staging array:
   $construct [] = $value;
  }
 
  // Then we collapse the staging array into the JSON form:
  $result = "[" . implode ( ", ", $construct ) . "]";
 }
 
 return $result;
}

if($_GET['enews']=='ok'){
    echo json_encode(array('a'=>'王进'));exit;
}
?>