Is there any reason for using => instead of = in PHP when assign a value to array?

Question

Please note that I have already read Reference — What does this symbol mean in PHP? and What Does This Mean in PHP -> or => and I know that what => do in PHP.

My question is different.

Generally most programming languages use = to assign value to another.

Example 01

$my_name = "I am the Most Stupid Person"; //Yes, that is my name in SO :-)

Example 02

$cars = array();

$cars[0] = "Volvo";
$cars[1] = "BMW";
$cars[2] = "Toyota";

Now let see following example.

$myArray = array(
    0 => 'Big',
    1 => 'Small',
    2 => 'Up',
    3 => 'Down'
);

Here is also what happen is we have assigned 'Big' for $myArray['0'].

But here we used => instead of =. Is there any special reason that PHP was designed that way?

Possible duplicate of [Use of => in PHP](https://stackoverflow.com/questions/1655336/use-of-in-php) — Masivuye Cokile, Sep 21 '17 at 11:03
Perhaps because `=` is specifically assignment of value on the right to variable on the left, and array keys aren't variables (they're array keys), so something else is needed as a symbol to represent that — Mark Baker, Sep 21 '17 at 11:03
[Related](https://stackoverflow.com/questions/6510705/php-array-syntax-operator)/maybe dupe? — James Thorpe, Sep 21 '17 at 11:05
@MasivuyeCokile It is not a duplicate for this question because I am asking why => use instead of =. Please don't mark questions as duplicate questions without reading question carefully. Please... — I am the Most Stupid Person, Sep 21 '17 at 11:09
@IamtheMostStupidPerson if you know the use of it then you would know why is it used instead of the assignment operator — Masivuye Cokile, Sep 21 '17 at 11:11
@MasivuyeCokile No I don't know and your linked question also NOT mentioned that why => used instead of =. — I am the Most Stupid Person, Sep 21 '17 at 11:15

Aurel Bílý · Accepted Answer · 2017-09-21T11:16:59.397

Consistency of syntax is important, here I would say using => in arrays is to ensure = still works. For example:

$a = 5;

Sets the variable $a to 5.

$a = $b = 5;

Sets the variable $a and $b to 5. That is = as an operator assigns the right hand side to the left hand side (if possible) and its result is also the right hand side. So now, in the context of an array:

$a = array(
    0 => 'foo'
  );

Now $a[0] is 'foo'.

$a = array(
    0 => $b = 'foo'
  );

Now $a[0] and $b are both 'foo'. Now think about this:

$b = 0;
$a = array(
    $b => 'foo'
  );

Simply means $a[$b], that is, $a[0] is 'foo'. If PHP used = for array keys:

$b = 1;
$a = array(
    $b = 'bar'
  );

What is the value of $a? Is it [1 => 'bar']? Or is it [0 => 'bar']? Did $b get the value 'bar'? Or was it only used as a key?

As you can see, the parser would be very confusing this way, and there would be no way to allow keys defined by variables with this syntax.

score 0 · Answer 2 · answered Sep 21 '17 at 11:07

0

It's because parser is written in that way.

Also it's more readable than $variable = "", witch means $variable now has value "" instead of 'key' => "" as In array at position 'key' there is value ""

answered Sep 21 '17 at 11:07

Justinas

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Is there any reason for using => instead of = in PHP when assign a value to array?

2 Answers2