PHP foreach change original array values

Question

I am very new in multi dimensional arrays  and this is bugging me big time   My array is as following    fields   array       names    gt  array            type            gt   text             class           gt   name             name            gt   name             text before     gt   name             value           gt                required        gt  true            Then i got a function checking if these inputs are filled in  if they are required   function checkForm  fields       foreach  fields as  field           if  field  required    amp  amp  strlen   POST  field  name      lt   0                fields  field   value      Some error                       return  fields      Now my problem is this line   fields  field   value      Some error     I want to change the content of the original array  since i am returning this  but how do I get the name of the current array  names in this example  in my foreach loop

User · Answer

Try this  function checkForm  fields           foreach  fields as  field               if  field  required    amp  amp  strlen   POST  field  name      lt   0                    field  value      Some error                                   return  field

User · Answer

In PHP  passing by reference   amp   is     controversial  I recommend not using it unless you know why you need it and test the results   I would recommend doing the following   foreach   fields as  key   gt   field        if   field  required    amp  amp  strlen   POST  field  name      lt   0             fields  key   value      Some error             So basically use  field when you need the values  and  fields  key  when you need to change the data

User · Answer

function checkForm  amp   fields       foreach  fields as  field           if  field  required    amp  amp  strlen   POST  field  name      lt   0                fields  field   value      Some error                       return  fields      This is what I would Suggest pass by reference

User · Answer

Use  amp   foreach  arr as  amp  value         value    newVal      amp  passes a value of the array as a reference and does not create a new instance of the variable  Thus if you change the reference the original value will change  PHP documentation for Passing by Reference Edit 2018 This answer seems to be favored by a lot of people on the internet  which is why I decided to add more information and words of caution  While pass by reference in foreach  or functions  is a clean and short solution  for many beginners this might be a dangerous pitfall     Loops in PHP don t have their own scope  -  Mark Amery  This could be a serious problem when the variables are being reused in the same scope  Another SO question nicely illustrates why that might be a problem     As foreach relies on the internal array pointer in PHP 5  changing it within the loop may lead to unexpected behavior  - PHP docs for foreach   Unsetting a record or changing the hash value  the key  during the iteration on the same loop could lead to potentially unexpected behaviors in PHP  lt  7  The issue gets even more complicated when the array itself is a reference   Foreach performance  In general  PHP prefers pass by value due to the copy-on-write feature  It means that internally PHP will not create duplicate data unless the copy of it needs to be changed  It is debatable whether pass by reference in foreach would offer a performance improvement  As it is always the case  you need to test your specific scenario and determine which option uses less memory and CPU time  For more information see the SO post linked below by NikiC   Code readability  Creating references in PHP is something that quickly gets out of hand  If you are a novice and don t have full control of what you are doing  it is best to stay away from references  For more information about  amp  operator take a look at this guide  Reference     What does this symbol mean in PHP  For those who want to learn more about this part of PHP language  PHP References Explained   A very nice technical explanation by  NikiC of the internal logic of PHP foreach loops  How does PHP   39 foreach  39  actually work

User · Answer

Use foreach  fields as  amp  field   - so you will work with the original array   Here is more about passing by reference

[php] PHP foreach change original array values

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