PHP function returning null on Ajax call - php

Question

I have an Ajax Call when tab is clicked in bootstrap 3.0
Below is the JS code
$('[data-toggle="tab"]').click(function (e) {
var $this = $(this);
loadtab = $this.attr('href');
if(loadtab=="#odhis"){
var email = $("#email");
$.ajax({
type: "POST",
url: "../orders.php",
data: {'email':email.val()},
dataType: "json",
success: function(response){
console.log(response);
},
error: function(xhr, status, error){
console.log(xhr.responseText);
}
});
}
});
PHP file orders.php
function getCustomOrderHistory(array $data){
$cstm = array();
if( !empty( $data ) ){
$trimmed_data = array_map('trim', $data);
$mail = mysqli_real_escape_string( $this->_con, $trimmed_data['email'] );
$checktable = "SELECT * from `orders` WHERE csmail='$mail'";
$resultcstm = mysqli_query($this->_con, $checktable);
while($row = mysqli_fetch_array($resultcstm)){
$cstm[] = $row;
}
}
return $cstm;
}
Now, when i print_r($cstm) then it prints the results in PHP file.
but in JS success response is empty.
Any help please?

Answer 1

Since your dataType: "json", instead of return just encode the $cstm array and echo it, like this:
function getCustomOrderHistory(array $data){
$cstm = array();
if( !empty( $data ) ){
$trimmed_data = array_map('trim', $data);
$mail = mysqli_real_escape_string( $this->_con, $trimmed_data['email'] );
$checktable = "SELECT * from `orders` WHERE csmail='$mail'";
$resultcstm = mysqli_query($this->_con, $checktable);
while($row = mysqli_fetch_array($resultcstm)){
$cstm[] = $row;
}
}
$json = json_encode($cstm);
echo $json;
}