php输出一个或多个字符串函数print()

<?php 
print "Hello world!"; 
?>

print(strings)

<?php
$str = "Hello world!";
print $str;
?>

<?php
$str = "Hello world!";
print $str;
print "<br>What a nice day!";
?>

<?php
$str1="Hello world!";
$str2="What a nice day!";
print $str1 . " " . $str2;
?>

<?php
$age=array("Peter"=>"35");
print "Peter is " . $age[&#39;Peter&#39;] . " years old.";
?>

<?php
print "This text
spans multiple
lines.";
?>

<?php
$color = "red";
print "Roses are $color";
print "<br>";
print &#39;Roses are $color&#39;;
?>