Don't encode json from php - php

Question

I have 2 files php: connect.php and getsp.php. As follow:
- Connect.php:
$host = "localhost";
$username = "root";
$password = "";
$database = "thietbi";
$conn = mysqli_connect($host, $username, $password, $database);
mysqli_query($conn, "SET NAMES 'uft8'");
- Getsp.php
include "connect.php";
// mysqli_set_charset($conn, "utf8");
$page = $_GET['page'];
$idsp = 1;
$space = 5;
$limit = ($page - 1) * $space;
$mangsanpham = array();
$query = "SELECT * FROM sanpham WHERE idsanpham = $idsp LIMIT $limit,$space";
$data = mysqli_query($conn,$query);
while ($row = mysqli_fetch_assoc($data)) {
$id = $row['id'];
$tsp = $row['tensanpham'];
$gsp = $row['giasanpham'];
$hsp = $row['hinhanhsanpham'];
$mtsp = $row['motasanpham'];
$isp = $row['idsanpham']));
array_push($mangsanpham, new Sanpham($id, $tsp, $gsp, $hsp, $mtsp, $isp));
}
echo json_encode($mangsanpham);
class Sanpham{
function Sanpham($id, $tensp, $giasp, $hinhsp, $motasp, $idsanpham){
$this->id = $id;
$this->tensp = $tensp;
$this->giasp = $giasp;
$this->hinhsp = $hinhsp;
$this->motasp = $motasp;
$this->idsanpham = $idsanpham;
}
}
When I run file "Getsp.php", result is white blank page.
I replace getsp.php with content:
include "connect.php";
// mysqli_set_charset($conn, "utf8");
$page = $_GET['page'];
$idsp = 1;
$space = 5;
$limit = ($page - 1) * $space;
$mangsanpham = array();
$query = "SELECT * FROM sanpham WHERE idsanpham = $idsp LIMIT $limit,$space";
$data = mysqli_query($conn,$query);
while ($row = mysqli_fetch_assoc($data)) {
array_push($mangsanpham, new Sanpham(
$row['id'],
$row['tensanpham'],
$row['giasanpham'],
$row['hinhanhsanpham'],
$row['motasanpham'],
$row['idsanpham']));
}
echo json_encode($mangsanpham);
class Sanpham{
function Sanpham($id, $tensp, $giasp, $hinhsp, $motasp, $idsanpham){
$this->id = $id;
$this->tensp = $tensp;
$this->giasp = $giasp;
$this->hinhsp = $hinhsp;
$this->motasp = $motasp;
$this->idsanpham = $idsanpham;
}
}
The result is not. Where did I wrong?
I tried 2 ways:
$json = json_encode($mangsanpham, JSON_PRETTY_PRINT);
print_r($json);
and
echo json_encode($mangsanpham);
The results are not encode JSON. Hope to get help from everyone!

Answer 1

To use array_push, you have to declare first variable as array
i.e $mangsanpham = array(); //before while loop