Tuesday, April 15, 2008

Difference between echo and print in PHP

1. Speed.  There is a difference between the two, but speed-wise it
should be irrelevant which one you use. echo is marginally faster
since
it doesn't set a return value if you really want to get down to the
nitty gritty.

2. Expression. print() behaves like a function in that you can do:
$ret = print "Hello World"; And $ret will be 1. That means that print
can be used as part of a more complex expression where echo cannot. An
example from the PHP Manual:

$b ? print "true" : print "false";

print is also part of the precedence table which it needs to be if it
is
to be used within a complex expression. It is just about at the bottom
of the precedence list though. Only "," AND, OR and XOR are lower.

3. Parameter(s). The grammar is: echo expression [, expression[,
expression] ... ] But echo ( expression, expression ) is not valid.
This would be valid: echo ("howdy"),("partner"); the same as: echo
"howdy","partner"; (Putting the brackets in that simple example
serves
no purpose since there is no operator precedence issue with a single
term like that.)

So, echo without parentheses can take multiple parameters, which get
concatenated:

echo "and a ", 1, 2, 3; // comma-separated without parentheses
echo ("and a 123"); // just one parameter with parentheses

print() can only take one parameter:

print ("and a 123");
print "and a 123";

From:
http://www.faqts.com/knowledge_base/view.phtml/aid/1/fid/40

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