json_encode doesn't display all array values [duplicate] - php

Question

This question already has answers here:
php json_encode not working on arrays partially
(2 answers)
Closed 5 years ago.
I have a PHP script where it fetches all records from a table and encodes it to JSON. The table has a total of 246 records. echo count(); returns 246 as well.
The problem is, whenever I use json_encode, it doesn't display the values from the array at all, all I see is a blank page. But if I reduce the number of records to 13 instead of 246, it works and it displays the encoded JSON result. I have also tried to increase the memory_limit at my php.ini file to 4095M, but no avail.
$result = mysqli_query($con, "SELECT * FROM cities");
if (mysqli_num_rows($result) > 0) {
$response["cities"] = array();
$city = array();
while($row = mysqli_fetch_assoc($result)) {
$city[] = $row;
array_push($response["cities"], $city);
}
$response["success"] = 1;
echo json_encode($response);
}

Answer 1

Try below and you'll get to know what is happening exactly:
$json = json_encode($response);
if ($json)
echo $json;
else
echo json_last_error_msg();
json_last_error_msg() - Returns the error string of the last json_encode() or json_decode() call

Answer 2

Array "city" is expanding for each call and you are pushing the complete array on each iteration in loop .
Try :
while($row = mysqli_fetch_assoc($result)) {
array_push($response["cities"], $row);
}
It should work

Answer 3

Remove $response array push $row into $cities array. After pushing all city set the city and response in json_encode(); function like this echo json_encode(array("cities"=>$cities, "success"=>1));
if (mysqli_num_rows($result) > 0) {
$cities = array();
while($row = mysqli_fetch_assoc($result)) {
array_push($cities, $row);
}
echo json_encode(array("cities"=>$cities, "success"=>1));
}