Php – PEAR error require_once(Structures/Graph/Node.php): failed to open stream

UPDATE: As of 2013 November and Ubuntu 12.04 these 2 commands should suffice:

sudo pear config-set auto_discover 1
sudo pear install pear.phpunit.de/PHPUnit

The following is an older answer. It's a known problem , although almost a year and a half had passed. Read about it here

The code coverage must be installed in order for phpunit to work properly

What you need to do is covered here:

code coverage installation through PEAR

Basically you have to type (with sudo if you don't have permissions, taken that phpunit is already installed):

pear channel-discover pear.phpunit.de
pear channel-discover components.ez.no
pear install phpunit/PHP_CodeCoverage

Incrementing / Decrementing Operators

++ increment operator

-- decrement operator

Example    Name              Effect
---------------------------------------------------------------------
++$a       Pre-increment     Increments $a by one, then returns $a.
$a++       Post-increment    Returns $a, then increments $a by one.
--$a       Pre-decrement     Decrements $a by one, then returns $a.
$a--       Post-decrement    Returns $a, then decrements $a by one.

These can go before or after the variable.

If put before the variable, the increment/decrement operation is done to the variable first then the result is returned. If put after the variable, the variable is first returned, then the increment/decrement operation is done.

For example:

$apples = 10;
for ($i = 0; $i < 10; ++$i) {
    echo 'I have ' . $apples-- . " apples. I just ate one.\n";
}

Live example

In the case above ++$i is used, since it is faster. $i++ would have the same results.

Pre-increment is a little bit faster because it really increments the variable and after that 'returns' the result. Post-increment creates a special variable, copies there the value of the first variable and only after the first variable is used, replaces its value with second's.

However, you must use $apples--, since first, you want to display the current number of apples, and then you want to subtract one from it.

You can also increment letters in PHP:

$i = "a";
while ($i < "c") {
    echo $i++;
}

Once z is reached aa is next, and so on.

Note that character variables can be incremented but not decremented and even so only plain ASCII characters (a-z and A-Z) are supported.

Stack Overflow Posts:

• Understanding Incrementing