php语法错误

<?php
for($i=1; $i<11; $i++)
{
echo $i //缺少结束符
}
?>

<?php
echo "Hello PHP&#39;;
?>

Parse error: syntax error, unexpected end of file, expecting variable (T_VARIABLE) or ${ (T_DOLLAR_OPEN_CURLY_BRACES) or {$ (T_CURLY_OPEN) in D:\AppServ\www\test\22\2\index.php on line 3

<?php
for($i=0; $i<10; $i++)
{
for($j=0; $j<10; $j++)
{
echo $i*$j."<br>";
}
?>

Parse error: syntax error, unexpected end of file in D:\AppServ\www\test\22\3\index.php on line 9

<?php
for( $i=1; $i<11; i++){//缺少一个变量的美元符号
echo $i."<br>";
}
?>

Parse error: syntax error, unexpected '++' (T_INC), expecting ')' in D:\AppServ\www\test\22\4\index.php on line 2