What Does "->" Mean/Refer to in PHP

What does - mean/refer to in PHP?

-> accesses a member of an object. So $wp_query->max_num_pages is accessing the field max_num_pages in the object $wp_query. It can be used to access either a method or a field belonging to an object, and if you're familiar with C++ or Java, it's equivalent to myObject.myField

Reference Guide: What does this symbol mean in PHP? (PHP Syntax)

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.

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Stack Overflow Posts:

• Understanding Incrementing

PHP &$string - What does this mean?

You are assigning that array value by reference.

passing argument through reference (&$) and by $ is that when you pass argument through reference you work on original variable, means if you change it inside your function it's going to be changed outside of it as well, if you pass argument as a copy, function creates copy instance of this variable, and work on this copy, so if you change it in the function it won't be changed outside of it

Ref: http://www.php.net/manual/en/language.references.pass.php

What does the variable $this mean in PHP?

It's a reference to the current object, it's most commonly used in object oriented code.

• Reference: http://www.php.net/manual/en/language.oop5.basic.php
• Primer: http://www.phpro.org/tutorials/Object-Oriented-Programming-with-PHP.html

Example:

<?php
class Person {
    public $name;

    function __construct( $name ) {
        $this->name = $name;
    }
};

$jack = new Person('Jack');
echo $jack->name;

This stores the 'Jack' string as a property of the object created.

What does =& mean in PHP?

It passes by reference. Meaning that it won't create a copy of the value passed.

See:
http://php.net/manual/en/language.references.php (See Adam's Answer)

Usually, if you pass something like this:

$a = 5;
$b = $a;
$b = 3;

echo $a; // 5
echo $b; // 3

The original variable ($a) won't be modified if you change the second variable ($b) . If you pass by reference:

$a = 5;
$b =& $a;
$b = 3;

echo $a; // 3
echo $b; // 3

The original is changed as well.

Which is useless when passing around objects, because they will be passed by reference by default.

What does = mean in PHP?

=> is the separator for associative arrays. In the context of that foreach loop, it assigns the key of the array to $user and the value to $pass.

Example:

$user_list = array(
    'dave' => 'apassword',
    'steve' => 'secr3t'
);

foreach ($user_list as $user => $pass) {
    echo "{$user}'s pass is: {$pass}\n";
}
// Prints: 
// "dave's pass is: apassword"
// "steve's pass is: secr3t"

Note that this can be used for numerically indexed arrays too.

Example:

$foo = array('car', 'truck', 'van', 'bike', 'rickshaw');
foreach ($foo as $i => $type) {
    echo "{$i}: {$type}\n";
}
// prints:
// 0: car
// 1: truck
// 2: van
// 3: bike
// 4: rickshaw

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