Initializing Arrays

[zaltek]

I have seen arrays in PHP initialized in the following ways:

$some_array1 = ...
$some_array2[] = ...

What's the difference between initializing arrays in these ways? Why do some require [] brackets and others don't?

[Fou-Lu]

Both are valid. Neither will throw an error in PHP assuming that $some_array2 isn't already in use as a scalar value.

PHP Code:

$a1 = array(); // valid
$a2 = []; // valid 5.4+
$a3[] = 'a val'; // valid 
$a4 = array('a val'); // valid

$a5 = new stdclass;
$a5[] = 'val'; // invalid.

$a6 = 'string';
$a6[] = 'string'; // invalid 


Typically I use $a = array(); since its clear its an array.

[zaltek]

PHP Code:

$a3[] = 'a val'; // valid 


So this means if I want to define an array with both an index and a value, I need to use the brackets next to the variable's name, right?