how to push content data to file in php code example

Example 1: write to file php

$myfile = fopen("newfile.txt", "w") or die("Unable to open file!");
fwrite($myfile, "Content to write to file");
fclose($myfile);

Example 2: file_put_contents php json file

$data[] = $_POST['data'];

$inp = file_get_contents('results.json');
$tempArray = json_decode($inp);
array_push($tempArray, $data);
$jsonData = json_encode($tempArray);
file_put_contents('results.json', $jsonData);