php显示空数组但ajax显示数据

Question

I am trying to use the data that AJAX sends in PHP but for some reason says that the array is empty I also don't get any errors from PHP or in my console. the console.log(data) shows the array with with the values of the selects. After the PHP there is HTML where the script.js is.console.log

index.php

 <?php
    error_reporting(-1);
    $value1 = "";
    $value2 = "";
    print_r($_POST); 
    if (isset($_POST['date']) && isset($_POST['date'])) {
        if (isset($_POST['date'])) {
            echo "Yes, mail is set";
            $value1 = $_POST['date'];
            $value2 = $_POST['quantity'];
        } else {
            echo "No, mail is not set";
        }
        exit;
    }
    echo $value1; 
    echo $value2;
    $canmakereservation = "https://www.planyo.com/rest/?method=can_make_reservation&api_key=YOURKEY&resource_id=110556&start_time=2018-04-25 09:00&end_time=2018-04-25 12:00&quantity=5";
    $cleancanmakereservation = preg_replace("/ /", "%20", $canmakereservation);
    $reservationavailable = file_get_contents("$cleancanmakereservation");
    $reservationAvailable = json_decode($reservationavailable, true);
    // echo "$cleancanmakereservation";
    // var_dump($reservationAvailable);
 ?>

script.js

$(document).ready(function(){

var date = "date";
var begin = "begin";
var eind = "eind";
var aantal = "aantal";


$('#datum').change(function() {
  date = $("#datum").val();
  console.log(date);
});
$('#beginTijd').change(function(){
    begin =( $(this).val() ); 
    console.log(begin);      
});
$('#Tijdsduur').change(function(){
    eind =( $(this).val() ); 
    console.log(eind);      
});
$('#aantalSloepen').change(function() {
aantal = ($(this).val());
console.log(aantal);
  $.ajax({
      type: "POST",
      url: "index.php",
      data: {
          date: begin,
          quantity: aantal
      },
      success: function(data) {
          alert(data);
          console.log(data);
      }
  });
});
});

Answer 1

First! There are duplicate conditions isset($_POST['date']) (3 times) in your code:

 if (isset($_POST['date']) && isset($_POST['date'])) {
        if (isset($_POST['date'])) {
            echo "Yes, mail is set";
            $value1 = $_POST['date'];
            $value2 = $_POST['quantity'];
        } else {
            echo "No, mail is not set";
        }
        exit;
    }

Second! You should remove exit; and try again!

Third: You should check your variable type, if your $value1 and $value2 is not a string, numeric. echo is false. try with return

EDIT:

Try this, it worked for me! the .php destination:

$value1 = "";
$value2 = "";
if (isset($_POST['date']) && isset($_POST['quantity'])) {

        echo "Yes, mail is set";
        $value1 = $_POST['date'];
        $value2 = $_POST['quantity'];
    }
    else {
        echo "No, mail is not set";
}
echo $value1;
echo $value2;

The ajax:

The result