String + foreach loop together in a variable in php

Question

I'm trying to loop through a json api response. I than need to write this to a table on a page through fopen(); I can loop through the first loop which loops the header of the table but i'm stuck at the second loop where the loop should the table data.

$arr = json_decode($response, true);

$domain = $arr['pricing'];

$header =  "<?php include '../includes/header.php'?>";

$footer =  "<?php include '../includes/footer.php'?>";


foreach ($domain as $tld => $result) {
    $tld_array[] = $tld;
};

foreach ($tld_array as $domain_tld) {

$tld_price = $arr['pricing'][$domain_tld]['register'][1];
$tld_price_transfer = $arr['pricing'][$domain_tld]['transfer'][1];
$tld_price_renewel = $arr['pricing'][$domain_tld]['renew'][1];

$myfile = fopen("domains.php", "w");
$txt = $header . '   
<section>
<div class="container">
    <h2 class="display-5  text-center mb-4 fw-bold my-5 p-2 p-sm-5">COMPARE PLANS</h2>
    <div class="table-responsive">
        <table class="table text-start">
            <thead>
                <tr>
                    <th>TLD</th>
                    <th>Registration</th>
                    <th>Transfer</th>
                    <th>Renewel</th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td>' . $domain_tld . '</td>
                    <td>' . $tld_price . '</td>
                    <td>' . $tld_price_transfer . '</td>
                    <td>' . $tld_price_renewel . '</td>/
                <tr>
            </tbody>
        </table>
    </div>
</div>
</section>
' . $footer;
fwrite($myfile, $txt);
fclose($myfile);
}

Answer 1

Code failed to copy the string contents

[Talking about string here, not the type string]

In C, a string is "... is a contiguous sequence of characters terminated by and including the first null character."

Code only copied pointers and not the string contents.

string key = argv[1];
string keyupper = argv[1];
string keylower = argv[1];

Comment discussion indicates OP now sees why code is in error.

Repaired code

//#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>

// Avoid naked magic numbers, instead define them
#define KEY_N 26

int main(int argc, string argv[]) {
    // Do not code argv[1] until after argc check
    // string key = argv[1];
    // string keyupper = argv[1];
    // string keylower = argv[1];

    if (argc != 2) {
        printf("Please input a key.\n");
        return 1;
    }

    char *key = argv[1];
    // else if (strlen(key) != 26)letters
    if (strlen(key) != KEY_N) {
        printf("Please make sure the key is 26 unique letters.\n");
        return 1;
    }

    char keyupper[KEY_N + 1];
    char keylower[KEY_N + 1];

    // for (int i = 0; i < 26; i++)
    for (size_t i = 0; i < KEY_N; i++) {
        // keyupper[i] = toupper(keyupper[i]);
        keyupper[i] = toupper((unsigned char) key[i]);
    }
    keyupper[KEY_N] = '\0';
    ...