• Jobs
  • About Us
  • professionals
    • Home
    • Jobs
    • Courses and challenges
  • business
    • Home
    • Post vacancy
    • Our process
    • Pricing
    • Assessments
    • Payroll
    • Blog
    • Sales
    • Salary Calculator

0

450
Views
While destructuring an array, can the same element value be accessed more than once?

Since PHP7.1, a foreach() expression can implement array destructuring as a way of unpacking row values and make individualized variable assignments.

When using array destructuring within a foreach() loop, can a specific value be accessed by its associative key more than once?

For example:

$array = [
    ['group' => 'A', 'name' => 'Ann', 'age' => 19],
    ['group' => 'B', 'name' => 'Bea', 'age' => 26],
    ['group' => 'A', 'name' => 'Cam', 'age' => 32],
    ['group' => 'B', 'name' => 'Des', 'age' => 24]
];

I know I can use:

foreach ($array as ['group' => $group, 'name' => $name, 'age' => $age]) {
    // do stuff with $group, $name, and $age
}

But what if I want to access, say, $group a second time while destructuring? Is it possible?

about 3 years ago · Santiago Trujillo
1 answers
Answer question

0

It looks pretty unorthodox and there will be very few scenarios when it is useful, but yes it is possible/valid.

Just repeat the "key => value" syntax again and provide a different variable in the value position. In this context, the keys may be repeated.

Here is a demonstration of using array destructuring to "pivot" a result set with a body-less foreach loop.

Code: (Demo)

$array = [
    ['group' => 'A', 'name' => 'Ann', 'age' => 19],
    ['group' => 'B', 'name' => 'Bea', 'age' => 26],
    ['group' => 'A', 'name' => 'Cam', 'age' => 32],
    ['group' => 'B', 'name' => 'Des', 'age' => 24]
];

$result = [];
foreach ($array as ['group' => $group, 'group' => $result[$group]['group'], 'name' => $name, 'age' => $result[$group][$name]]);
# 1st assignment of group value^^^^^^
# 2nd assignment of group value-------------------^^^^^^^^^^^^^^^^^^^^^^^^

var_export($result);

Output:

array (
  'A' => 
  array (
    'group' => 'A',
    'Ann' => 19,
    'Cam' => 32,
  ),
  'B' => 
  array (
    'group' => 'B',
    'Bea' => 26,
    'Des' => 24,
  ),
)

The same technique works outside of the context of a foreach() loop as well. (Demo)

['one' => $result[], 'one' => $result[]] = ['one' => 1];
var_export($result);

Output:

array (
  0 => 1,
  1 => 1,
)
about 3 years ago · Santiago Trujillo Report
Answer question
Find remote jobs

Discover the new way to find a job!

Top jobs
Top job categories
Business
Post vacancy Pricing Our process Sales
Legal
Terms and conditions Privacy policy
© 2025 PeakU Inc. All Rights Reserved.

Andres GPT

Recommend me some offers
I have an error