echo variable in html form - php

Question

I'm trying to echo a value in a form based on number of rows returned from database query. Keep getting error Parse error: syntax error, unexpected T_ECHO, expecting ',' or ';'
As you can probably tell I'm pretty new to this. Can anyone help me echo the variable? I know that $num_rows is returning a value as using var_dump shows. Thanks
<?
if($num_rows <= 10) {
echo '</br></br><form id="h1" class="rounded" action="4.php" target=""
method="post"/>
<input type="submit" name="submit" class="button" value="10" /><br>
<input type="text" name="number_of_tests" value="'echo $num_rows;'"/>
</form>';
}
if($num_rows >10) {
echo '</br></br><form id="h2" class="rounded" action="4.php"
target="_blank" method="post"/>
<input type="submit" name="submit" class="button" value="11"/><BR>
<input type="text" name="number_of_tests" value="'echo $num_rows;'"/>
</form>';
}?>

Answer 1

In both of your code blocks, you repeat the command echo instead of either concatenating the output or using two statements. You have done this:
echo '</br></br><form id="h1" class="rounded" action="4.php" target=""
method="post"/>
<input type="submit" name="submit" class="button" value="10" /><br>
<input type="text" name="number_of_tests" value="'echo $num_rows;'"/>
</form>';
which is a syntax error. Instead, you can do this:
echo '</br></br><form id="h1" class="rounded" action="4.php" target=""
method="post"/>
<input type="submit" name="submit" class="button" value="10" /><br>
<input type="text" name="number_of_tests" value="' . $num_rows . '"/>
</form>';
or this:
echo '</br></br><form id="h1" class="rounded" action="4.php" target=""
method="post"/>
<input type="submit" name="submit" class="button" value="10" /><br>
<input type="text" name="number_of_tests" value="';
echo $num_rows . '"/>';
echo '</form>';

Answer 2

This is the code you should use to concatenate strings and output the result
echo ' some value ' . $variable . ' other text ';
The echo function outputs a string, while the dot (.) operator concatenates strings. This is the kind of wrong code
echo 'value="'echo $num_rows;'"/>';
When you want to insert the value of a variable this is the way
$a_string = 'I\'m a string';
echo "I'm a double quoted string and can contain a variable: $a_string";
This works with arrays too
$an_array = array('one', 'two', 'three');
echo "The first element of the array is {$an_array[0]}"
See the PHP manual