Php.net Functions

Front 1

What is the difference between echo() and print()?

Back 1

Echo is not actually a function, but a language construct; thus you don't need to use parentheses. No value is returned.

Print is also a language construct, but always returns a value of 1.

Front 2

What tags can be used to shortcut echo()?

Back 2

<?= expression ?> This is a shortcut for "<? echo expression ?>"

<%= $variable; # This is a shortcut for "<% echo . . ." %>

NOTE: It is possible to have both styles of shortcut tags disabled in PHP.ini, so they are not recommend.

Front 3

How can you get the variable type for a variable?

Back 3

gettype()

GetType($var1) will return the human readable form (integer, float, string, etc) of the variable.

Also...

var_dump()

Will return type and number

Example:
<?php

$b = 3.1;
$c = true;
var_dump($b, $c);

?>

Returns:

float(3.1)
bool(true)

Front 4

What is the difference between a type-cast and using the SetType() function?

Back 4

Using a type-cast will temporary convert the var to the new type for that expression, but not change var type. SetType() will actually change the var type.

Example:

$b = 0;
echo var_dump((bool)$b);
echo var_dump($b);
settype($b, "bool");
echo var_dump($b);

Returns:
bool(false)
int(0)
bool(false)

Front 5

What does the print_r() function do?

Back 5

Prints human readable information about a variable.

print_r($var);

or

$results = print_r($var1, true); //Returns data to var $results