<?php
$string = "<b>I like 'PHP' & I think it is \"cool\"</b>";
var_dump(htmlentities($string, ENT_QUOTES));
var_dump(print htmlspecialchars($string));
string(78) "<b>I like 'PHP' & I think it is "cool"</b>"
<b>I like 'PHP' & I think it is "cool"</b>int(1)
string(78) "<b>I like 'PHP' & I think it is "cool"</b>"
<b>I like 'PHP' & I think it is "cool"</b>int(1)