PHP DateTimeImmutable::modify()

http://www.php.net/manual/en/datetimeimmutable.modify.php

by TeMPOraL • 12 years ago

34 19 12 years ago

mherdeg• 12 years ago

Some discussion about this method at http://derickrethans.nl/immutable-datetime.html

nkozyra2• 12 years ago

That seems to explain the logic of having an immutable DateTime type (to avoid breaking backwards compatibility with the inherently mutable old DateTime) but doesn't explain the logic of then including a modify() method for such objects.

"Immutable" probably isn't the right description.

arankine• 12 years ago

The method returns a new instance, so it is still immutable, technically.

pilif2• 12 years ago

objects of the DateTimeImmutable class are immutable. All methods that modify the object will return a new copy.

While the naming is a bit unfortunate, this isn't different from other languages that have immutable types like Java String which also have methods that act on the string they are called on and return a new copy.

Like concat().

    String foo = "foo";
    String foobar = foo.concat("bar");
    // foo is still set to "foo"

And with datetimeimmutable:

    $date = new DateTimeImmutable();
    $other_date = $date->modify('+ 3 days');
    // $date still is today.

Python strings work the same. And all the ruby string methods not ending with a bang also work the same.

The reason why the method is called 'modify' in PHP is because the old DateTime (mutable edition™) method was also called 'modify' and the two should be more or less drop-in replacements.

Besides - what would you call a method that modifies a timestamp?

ebbv• 12 years ago

This is one of those things that seems hilarious only because you are ignorant of what's actually happening. Being proud of finding this funny is being proud of your own ignorance.

rabbyte• 12 years ago

You could explain what's actually happening instead of ridiculing people for not knowing.

Timmmmbob• 12 years ago

According to the comments it returned a modified immutable date. The original date is not modified.

Poor function naming perhaps, (should be `modified()`), but it's not really one of the things that makes PHP infamous.

PHP DateTimeImmutable::modify()

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