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Comparing Period objects

You can compare different Period objects according to their datepoints or durations.

Using datepoints

Period::isBefore

Description

<?php

public Period::isBefore(mixed $index): bool

Tells whether the current Period object datetime continuum is entirely before the specified $index.

Parameter

The $index argument can be another Period object or a datepoint.

Example

<?php

use League\Period\Period;

//comparing a datetime
$period = Period::createFromMonth(1983, 4);
$alt = Period::createFromMonth(1984, 4);
$period->isBefore($alt); //returns true;
$alt->isBefore($period); //return false;

Period::isAfter

Description

<?php

public Period::isBefore(mixed $index): bool

Tells whether the current Period object datetime continuum is entirely after the specified $index.

Parameter

The $index argument can be another Period object or a datepoint.

Example

<?php

use League\Period\Period;

//comparing a datetime
$period = Period::createFromMonth(1983, 4);
$alt = Period::createFromMonth(1984, 4);
$alt->isAfter($period); //returns true;
$period->isAfter($alt); //return false;

Period::abuts

Description

<?php

public Period::abuts(Period $index): bool

A Period abuts if it starts immediately after, or ends immediately before the submitted Period without overlapping.

Example

<?php

use League\Period\Period;

$period        = Period::createFromMonth(2014, 3);
$anotherPeriod = Period::createFromMonth(2014, 4);
$period->abuts($anotherPeriod); //return true
//in this case $period->getEndDate() == $anotherPeriod->getStartDate();

Period::overlaps

Description

<?php

public Period::overlaps(Period $period): bool

A Period overlaps another if they share some common part of their respective datetime continuum without abutting.

Example

<?php

use League\Period\Period;

$orig  = Period::createFromMonth(2014, 3);
$alt   = Period::createFromMonth(2014, 4);
$other = Period::createFromDuration('2014-03-15', '3 WEEKS');

$orig->overlaps($alt);   //return false
$orig->overlaps($other); //return true
$alt->overlaps($other);  //return true

Period::sameValueAs

Description

<?php

public Period::sameValueAs(Period $period): bool

Tells whether two Period objects shares the same datepoints.

Example

<?php

use League\Period\Period;

$orig  = Period::createFromMonth(2014, 3);
$alt   = Period::createFromMonth(2014, 4);
$other = Period::createFromDuration('2014-03-01', '1 MONTH');

$orig->sameValueAs($alt);   //return false
$orig->sameValueAs($other); //return true

Period::contains

Description

<?php

public Period::contains(mixed $index): bool

A Period contains a datepoint reference if this datepoint is present in its datetime continuum.
A Period contains another Period object if the latter datetime continuum is completely contained within the Period datetime continuum.

Parameter

The $index argument can be another Period object or a datepoint.

Example

<?php

use League\Period\Period;

//comparing a datetime
$period = Period::createFromMonth(1983, 4);
$period->contains('1983-04-15');      //returns true;
$period->contains($period->getEndDate()); //returns false;

//comparing two Period objects
$alt = Period::createFromDuration('1983-04-12', '12 DAYS');
$period->contains($alt); //return true;
$alt->contains($period); //return false;

Period::diff

Description

<?php

public Period::diff(Period $period): array

This method returns the difference between two Period objects only if they actually do overlap. If they do not overlap or abut, then an Exception is thrown.

The difference is expressed as an array. The returned array:

is empty if both objects share the same datepoints;
contains one Period object if both objects share only one datepoint;
contains two Period objects if no datepoint are shared between objects. The first Period datetime continuum is always entirely set before the second one;

Example

<?php

use League\Period\Period;

$orig = Period::createFromDuration('2013-01-01', '1 MONTH');
$alt  = Period::createFromDuration('2013-01-15', '7 DAYS');
$diff = $period->diff($alt);
// $diff is an array containing 2 Period objects
// the first object is equal to new Period('2013-01-01', '2013-01-15');
// the second object is equal to new Period('2013-01-23', '2013-02-01');
$diff[0]->isBefore($diff[1]); //return true;
//this is always true when two Period objects are present

Before getting the difference, make sure the Period objects, at least, overlap each other.

Period::intersect

Description

<?php

public function intersect(Period $period): Period

An Period overlaps another if it shares some common part of the datetime continuum. This method returns the amount of the overlap as a Period object, only if they actually do overlap. If they do not overlap or abut, then an Exception is thrown.

Before getting the intersection, make sure the Period objects, at least, overlap each other.

Example

<?php

use League\Period\Period;

$period        = Period::createFromDuration('2012-01-01', '2 MONTHS');
$anotherPeriod = Period::createFromDuration('2012-01-15', '3 MONTHS');
$intersectPeriod = $period->intersect($anotherPeriod);

Period::gap

Description

<?php

public function gap(Period $period): Period

A Period has a gap with another Period if there is a non-zero interval between them. This method returns the amount of the gap as a new Period object only if they do actually have a gap between them. If they overlap a Exception is thrown.

Before getting the gap, make sure the Period objects do not overlaps.

Example

<?php

use League\Period\Period;

$orig = Period::createFromDuration('2012-01-01', '2 MONTHS');
$alt  = Period::createFromDuration('2013-01-15', '3 MONTHS');
$gapPeriod = $orig->gap($alt);

Using durations

Sorting objects

Description

<?php

public Period::compareDuration(Period $period): int
public Period::durationGreaterThan(Period $period): bool
public Period::durationLessThan(Period $period): bool
public Period::sameDurationAs(Period $period): bool

The method Period::compareDuration compares two Period objects according to their duration. The method returns:

1 if the current object duration is greater than the submitted object duration;
-1 if the current object duration is lesser than the submitted object duration;
0 if the current object duration is equal to the submitted object duration;

To ease the method usage you can rely on the following proxy methods:

Period::durationGreaterThan returns true when Period::compareDuration returns 1
Period::durationLessThan returns true when Period::compareDuration returns -1
Period::sameDurationAs returns true when Period::compareDuration returns 0

Examples

<?php

$orig  = Period::createFromDuration('2012-01-01', '1 MONTH');
$alt   = Period::createFromDuration('2012-01-01', '1 WEEK');
$other = Period::createFromDuration('2013-01-01', '1 MONTH');

$orig->compareDuration($alt);     //return 1
$orig->durationGreaterThan($alt); //return true
$orig->durationLessThan($alt);    //return false

$alt->compareDuration($other);     //return -1
$alt->durationLessThan($other);    //return true
$alt->durationGreaterThan($other); //return false

$orig->compareDuration($other);   //return 0
$orig->sameDurationAs($other);    //return true
$orig->sameValueAs($other);       //return false
//the duration between $orig and $other are equals but not the datepoints!!

Returning the duration differences

Description

<?php

public Period::dateIntervalDiff(Period $period): DateInterval
public Period::timestampIntervalDiff(Period $period): float

Return the duration difference between two Period objects using a DateInterval object or expressed in seconds.

Examples

<?php

use League\Period\Period;

$period    = Period::createFromSemester(2012, 1);
$altPeriod = Period::createFromWeek(2012, 4);
$diff = $period->dateIntervalDiff($altPeriod);
// $diff is a DateInterval object
$diff_as_seconds = $period->timestampIntervalDiff($altPeriod);
//$diff_as_seconds represents the interval expressed in seconds