<!DOCTYPE HTML>
<html>
<head>
<title>PHP: Variable</title>
</head>
<body>
<?php
echo "<h1>Hello World!</h1>";
?>
<?php
// create an init a varaible
$body_temp = 98.6;
// display the variable value
echo $body_temp; // echo is equivalent to print, not println
// display the variable value substituted in a mixed string
echo "<p>Body temperature is $body_temp degree Fahrenheit";
// now, assign a new value to the variable
$body_temp = 37.0;
// display the new variable substitied in a mixed string
echo " ( $body_temp degrees Celsius )</p>";
$str1 = "If you are \"happy\" and you 'know' it ... "; // use "escape" character (\) for quote inside qoute
$str2 = "clap your hand!";
$str = $str1 . $str2;
echo $str."<br />";
print "body_temp is " . $body_temp .'<br/>';
print("body_temp is " . $body_temp .'<br/>');
printf("body_temp is " . $body_temp .'<br/>');
printf("body_temp is %5.3f" , $body_temp , '<br/>');
?>
</body>
</html>