解决php中文乱码的问题

<?php
$sum=0;
$total=1.2;
$sum=$total;
echo gettype($sum);
echo &#39;</br>&#39;;
$sum1=0;
$total1=$sum;
echo gettype($total1);//获取变量的类型
$sum3=100;
echo &#39;</br>&#39;;
settype($sum,"string");//设置变量的类型
echo gettype($sum3);
echo &#39;</br>&#39;;
echo &#39;判断一个变量是否存在:&#39;;
$a=5;
echo isset($a);
?>

header("content-type:text/html;charset=utf-8");

';
$sum1=0;
$total1=$sum;
echo gettype($total1);//获取变量的类型
$sum3=100;
echo '
';
settype($sum,"string");//设置变量的类型
echo gettype($sum3);
echo '
';
echo '判断一个变量是否存在:';
$a=5;
echo isset($a);
?>