What does "=>" mean in PHP?

What does the => operator mean in the following code?

foreach ($user_list as $user => $pass)

The code is a comment at PHP.net. The user does not specify the value of $user_list , $user or $pass. I normally see that => means equal or greater than.

However, I am not sure about its purpose here because it is not assigned. I read the code as

process a list of users in integers

such that the value of each user is equal or greater than password

The above does not make sense to me.

---

=> 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

---

It means assign the key to $user and the variable to $pass

When you assign an array, you do it like this

$array = array("key" => "value");

It uses the same symbol for processing arrays in foreach statements. The '=>' links the key and the value.

According to the PHP Manual, the '=>' created key/value pairs.

Also, Equal or Greater than is the opposite way: '>='. In PHP the greater or less than sign always goes first: '>=', '<='.

And just as a side note, excluding the second value does not work like you think it would. Instead of only giving you the key, It actually only gives you a value:

$array = array("test" => "foo");

foreach($array as $key => $value)
{
    echo $key . " : " . $value; // Echoes "test : foo"
}

foreach($array as $value)
{
    echo $value; // Echoes "foo"
}

---

Code like "a => b" means, for an associative array (some languages, like Perl, if I remember correctly, call those "hash"), that 'a' is a key, and 'b' a value.

You might want to take a look at the documentations of, at least:

foreach

arrays

Here, you are having an array, called $user_list , and you will iterate over it, getting, for each line, the key of the line in $user , and the corresponding value in $pass .

For instance, this code:

$user_list = array(
    'user1' => 'password1',
    'user2' => 'password2',
);

foreach ($user_list as $user => $pass)
{
    var_dump("user = $user and password = $pass");
}

Will get you this output:

string 'user = user1 and password = password1' (length=37)
string 'user = user2 and password = password2' (length=37)

(I'm using var_dump to generate a nice output, that facilitates debuging; to get a normal output, you'd use echo )

"Equal or greater" is the other way arround: "greater or equals", which is written, in PHP, like this; ">="
The Same thing for most languages derived from C: C++, JAVA, PHP, ...

As a piece of advice: If you are just starting with PHP, you should definitely spend some time (maybe a couple of hours, maybe even half a day or even a whole day) going through some parts of the manual :-)
It'd help you much!

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