Important changes in PHP 8

Topic index on this page

• The way that automatic numbering works ( PHP 8.0)
• Comparison between numbers and strings ( PHP 8.0)
• The words ´match´ and ´mixed´ are now reserved keywords (PHP 8.0)

The way that automatic numbering works

If you create an array with the first key as a negative number, subsequent keys will add 1 to the previous number. Prior to PHP 8, subsequent keys after a negative number always started from zero.

<?php

//php >= 8.x
  $myArray[-3] = 'R';
  array_push($myArray, 'T', 'Y');
  print_r($myArray);
/*OUTPUT 
Array
(
    [-3] => R
    [-2] => T
    [-1] => Y
)*/

//php < 8.x
  $myArray[-3] = 'R';
  array_push($myArray, 'T', 'Y');
  print_r($myArray);
/*OUTPUT 
Array
(
    [-3] => R
    [0] => T
    [1] => Y
)
)*/

<?php

//php >= 8.x
  $myArray[-3] = 'R';
  array_push($myArray, 'T', 'Y');
  print_r($myArray);
/*OUTPUT 
Array
(
    [-3] => R
    [-2] => T
    [-1] => Y
)*/

//php < 8.x
  $myArray[-3] = 'R';
  array_push($myArray, 'T', 'Y');
  print_r($myArray);
/*OUTPUT 
Array
(
    [-3] => R
    [0] => T
    [1] => Y
)
)*/

Comparison between numbers and strings

PHP 8 changes the way the loose comparison operator == compares numbers to strings. Now it converting the number to a string and testing whether they’re the same.

Before, the comparison was performed converting the string to a number, and it may seem bizarre, but previously any string compared no started in a numeral was converted to zero, what using the == operator would return true. Now all this sentenses (0 == “not-a-number”) are false:

0 == "foo" is false

0 == "" is false

0 == "0" is true

0 === "0" is false

The words ´match´ and ´mixed´ are now reserved keywords