Echo is not a function but it is a constructor, So you are not require parentheses with it. Echo simply mean output all parameters.

How echo is used in PHP.

Echo As String:

<?php

echo “Hello Neepan Tech”;

?>

Echo with Concatenation:

<?php

echo “Hello” . “Neepan Tech”;

?>

Combining two string with the help of echo.

Echo with HTML TAGS:

<?php

echo “Hello” ;

echo “<br />”;

echo “Neepan Tech”;

echo “Html Tags are used in echo in php. <br />”;

?>

Echo with Variable:

<?php

$var1=10;

echo $var1;

echo ” Or it can be used as” . “<br />”;

echo “$var1″;

?>

Echo with Function:

<?php

$a=”Hello Neepan Tech”;

echo strlen($a);

?>

Echo is used to output any parameters. like variable, string, function,  HTML Tags,  Concatenation.