How to insert a new key value pair in array in php?

Question

I've an array as follows named $test_package_data. For the reference I'm printing first two elements of it:

Array (     [0] => Array         (             [test_pack_id] => 9f27643023a83addd5eed41c4aade840             [test_pack_name] => Exams Combo             [test_pack_desc] => This Package contains 24 tests of Reasoning, English and Quantitative Aptitude.  Total Tests in this Package : 26             [test_pack_type_id] => 3             [test_pack_image] =>              [test_pack_validity_year] => 0             [test_pack_validity_month] => 3             [test_pack_validity_days] => 0             [test_pack_plan] => paid             [test_pack_price] => 399.00             [test_pack_no_tests] => 0             [test_pack_publish] => yes             [test_pack_sold] => 1             [test_pack_created_staff_id] => ff8d4a5ea6bf11dce105aa2fa7b959b8             [test_pack_updated_staff_id] => 81c4e3607c7e56bbf5461ef150437675             [test_pack_created_date] => 303             [test_pack_updated_date] => 1349235701             [test_pack_purchase_date] => 255             [category_detail] => Array                 (                     [0] => Array                         (                             [test_pack_category_id] => 8                             [category_name] => English Language                             [test_detail] => Array                                 (                                     [0] => Array                                         (                                             [test_id] => 91                                             [test_name] => English Language 8                                         )                                      [1] => Array                                         (                                             [test_id] => 90                                             [test_name] => English Language 7                                         )                                      [2] => Array                                         (                                             [test_id] => 88                                             [test_name] => English Language 6                                         )                                      [3] => Array                                         (                                             [test_id] => 89                                             [test_name] => English Language 5                                         )                                      [4] => Array                                         (                                             [test_id] => 87                                             [test_name] => English Language 4                                         )                                      [5] => Array                                         (                                             [test_id] => 86                                             [test_name] => English Language 3                                         )                                      [6] => Array                                         (                                             [test_id] => 85                                             [test_name] => English Language 2                                         )                                      [7] => Array                                         (                                             [test_id] => 97                                             [test_name] => English Language 1                                         )                                  )                          )                      [1] => Array                         (                             [test_pack_category_id] => 4                             [category_name] => All Subjects                             [test_detail] => Array                                 (                                     [0] => Array                                         (                                             [test_id] => 93                                             [test_name] => Mega 2                                         )                                      [1] => Array                                         (                                             [test_id] => 92                                             [test_name] => Mega 1                                         )                                  )                          )                      [2] => Array                         (                             [test_pack_category_id] => 7                             [category_name] => Quantitative Aptitude                             [test_detail] => Array                                 (                                     [0] => Array                                         (                                             [test_id] => 83                                             [test_name] => Quantitative Aptitude 8                                         )                                      [1] => Array                                         (                                             [test_id] => 82                                             [test_name] => Quantitative Aptitude 7                                         )                                      [2] => Array                                         (                                             [test_id] => 81                                             [test_name] => Quantitative Aptitude 6                                         )                                      [3] => Array                                         (                                             [test_id] => 80                                             [test_name] => Quantitative Aptitude 5                                         )                                      [4] => Array                                         (                                             [test_id] => 79                                             [test_name] => Quantitative Aptitude 4                                         )                                      [5] => Array                                         (                                             [test_id] => 78                                             [test_name] => Quantitative Aptitude 3                                         )                                      [6] => Array                                         (                                             [test_id] => 77                                             [test_name] => Quantitative Aptitude 2                                         )                                      [7] => Array                                         (                                             [test_id] => 76                                             [test_name] => Quantitative Aptitude 1                                         )                                  )                          )                      [3] => Array                         (                             [test_pack_category_id] => 6                             [category_name] => Logical Reasoning                             [test_detail] => Array                                 (                                     [0] => Array                                         (                                             [test_id] => 75                                             [test_name] => Reasoning 8                                         )                                      [1] => Array                                         (                                             [test_id] => 74                                             [test_name] => Reasoning 7                                         )                                      [2] => Array                                         (                                             [test_id] => 73                                             [test_name] => Reasoning 6                                         )                                      [3] => Array                                         (                                             [test_id] => 72                                             [test_name] => Reasoning 5                                         )                                      [4] => Array                                         (                                             [test_id] => 71                                             [test_name] => Reasoning 4                                         )                                      [5] => Array                                         (                                             [test_id] => 70                                             [test_name] => Reasoning 3                                         )                                      [6] => Array                                         (                                             [test_id] => 69                                             [test_name] => Reasoning 2                                         )                                      [7] => Array                                         (                                             [test_id] => 68                                             [test_name] => Reasoning 1                                         )                                  )                          )                  )          )      [1] => Array         (             [test_pack_id] => e7e95de96987cc7c89c1f0183110fb38             [test_pack_name] => Aptitude Reasoning             [test_pack_desc] => This package contains 8 tests on Reasoning.             [test_pack_type_id] => 3             [test_pack_image] =>              [test_pack_validity_year] => 0             [test_pack_validity_month] => 3             [test_pack_validity_days] => 0             [test_pack_plan] => free             [test_pack_price] => 0.00             [test_pack_no_tests] => 0             [test_pack_publish] => yes             [test_pack_sold] => 4             [test_pack_created_staff_id] => ff8d4a5ea6bf11dce105aa2fa7b959b8             [test_pack_updated_staff_id] => ff8d4a5ea6bf11dce105aa2fa7b959b8             [test_pack_created_date] => 303             [test_pack_updated_date] => 1347127387             [test_pack_purchase_date] => 110             [category_detail] => Array                 (                     [0] => Array                         (                             [test_pack_category_id] => 6                             [category_name] => Logical Reasoning                             [test_detail] => Array                                 (                                     [0] => Array                                         (                                             [test_id] => 75                                             [test_name] => Reasoning 8                                         )                                      [1] => Array                                         (                                             [test_id] => 74                                             [test_name] => Reasoning 7                                         )                                      [2] => Array                                         (                                             [test_id] => 73                                             [test_name] => Reasoning 6                                         )                                      [3] => Array                                         (                                             [test_id] => 72                                             [test_name] => Reasoning 5                                         )                                      [4] => Array                                         (                                             [test_id] => 71                                             [test_name] => Reasoning 4                                         )                                      [5] => Array                                         (                                             [test_id] => 70                                             [test_name] => Reasoning 3                                         )                                      [6] => Array                                         (                                             [test_id] => 69                                             [test_name] => Reasoning 2                                         )                                      [7] => Array                                         (                                             [test_id] => 68                                             [test_name] => Reasoning 1                                         )                                  )                          )                  )          ) ) 

Now I want to add a new key-value pair named [count] => '$some_value' in this array in every element after the key-value pair [test_pack_purchase_date](say after [test_pack_purchase_date] => 255. How should I do this? Can anyone help me in this regard? Thanks in advance.

Answer 1

If you are creating new array then try this :

$arr = ['key' => 'value'];

And if array is already created then try this :

$arr['key'] = 'value';