PHP JSON foreach麻烦

I create a json structure with this php code:

<?php
    include "../base.php";

            $STH = $DBH->prepare("SELECT * FROM customers");
            $STH->execute();

            $result = $STH->fetchall(PDO::FETCH_ASSOC);
            $rows = $STH->rowCount();

            $jsontext = "{";
            $jsontext .= "total: ".$rows.",";
            $jsontext .= "page: 0,";
            $jsontext .= "records: [";

            foreach($result as $key => $inner_arr) {
                $jsontext .= "{";
                foreach($inner_arr as $field_name => $field_value) {
                    $jsontext .= "{$field_name}: {$field_value}, ";
                }
                $jsontext .= "},";
            }

            $jsontext .= "]";
            $jsontext .= "}";
    echo json_encode($jsontext);
?>

the main problem is this line $jsontext .= "{$field_name}: {$field_value}, ";

When I print the whole script with "echo" it works. But with $jsontext .= it is not working and I receive only "null".

try using json_encode built in function

json_encode

thank you to @Satya and @keune.

changing the last line from

echo json_encode($jsontext);

to

echo $jsontext;

solves the problem.

Try:

            $STH = $DBH->prepare("SELECT * FROM customers");
            $STH->execute();

            $result = $STH->fetchall(PDO::FETCH_ASSOC);
            $rows = $STH->rowCount();

            $jsontext['total'] = $rows;
            $jsontext['page'] = 0;

            foreach($result as $key => $inner_arr) {
                foreach($inner_arr as $field_name => $field_value) {
                    $jsontext['records'][][$field_name] = $field_value;
                }
            }
    echo json_encode($jsontext);
?>

p. s. i didnt tested it.

Replace

json_encode($jsontext);

with

echo $jsontext;