PHP echo function

echo

(PHP 3, PHP 4, PHP 5)

echo -- Output one or more stringsDescriptionvoid echo ( string arg1 [, string ...] )

Outputs all parameters.

echo() is not actually a function (it is a
language construct), so you are not required to use parentheses
with it. echo() (unlike some other language
constructs) does not behave like a function, so it cannot
always be used in the context of a function. Additionally, if you want to
pass more than one parameter to echo(), the parameters
must not be enclosed within parentheses.

Example 1. echo() examples

echo "Hello World";

echo "This spans
multiple lines. The newlines will be
output as well";

echo "This spans\nmultiple lines. The newlines will be\noutput as well.";

echo "Escaping characters is done \"Like this\".";

// You can use variables inside of an echo statement
$foo = "foobar";
$bar = "barbaz";

echo "foo is $foo"; // foo is foobar

// You can also use arrays
$bar = array("value" => "foo");

echo "this is {$bar['value']} !"; // this is foo !

// Using single quotes will print the variable name, not the value
echo 'foo is $foo'; // foo is $foo

// If you are not using any other characters, you can just echo variables
echo $foo; // foobar
echo $foo,$bar; // foobarbarbaz

// Some people prefer passing multiple parameters to echo over concatenation.
echo 'This ', 'string ', 'was ', 'made ', 'with multiple parameters.', chr(10);
echo 'This ' . 'string ' . 'was ' . 'made ' . 'with concatenation.' . "\n";

echo <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon. no extra whitespace!
END;

// Because echo does not behave like a function, the following code is invalid.
($some_var) ? echo 'true' : echo 'false';

// However, the following examples will work:
($some_var) ? print 'true' : print 'false'; // print is also a construct, but
// it behaves like a function, so
// it may be used in this context.
echo $some_var ? 'true': 'false'; // changing the statement around

echo() also has a shortcut syntax, where you can
immediately follow the opening tag with an equals sign. This short syntax
only works with the short_open_tag configuration setting
enabled.

I have <?=$foo[/php] foo.

For a short discussion about the differences between
print() and echo(), see this FAQTs
Knowledge Base Article: http://www.faqts.com/knowledge_base/view.phtml/aid/1/fid/40

Note: Because this is a
language construct and not a function, it cannot be called using
variable functions

See also
print(),
printf(), and
flush().