How to create an empty array in PHP with predefined size

Question

I am creating a new array in a for loop   for  i  lt   number of items      data  i     some data    PHP keeps complaining about the offset since for each iteration I add a new index for the array  which is kind of stupid    Notice  Undefined offset  1 in include    line 23 of      Notice  Undefined offset  1 in include    line 23 of     Notice  Undefined offset  1 in include    line 23 of         Is there some way to predefine the number items in the array so that PHP will not show this notice   In other words  can I predefine the size of the array in a similar way to this    myarray   array  size of the earray

User · Answer

You can t predefine a size of an array in php  A good way to acheive your goal is the following      Create a new array   array   array         Add an item while  i  lt  yourWantedItemQuantity for   i   0   i  lt   number of items   i          array push  array   some data         or  array      some data  for single items      Note that it is way faster to use array fill   to fill an Array     array   array fill 0  number of items   some data     If you want to verify if a value has been set at an index  you should use the following  array key exists  key    array  or isset  array  key     See array key exists    isset and array fill

User · Answer

There is no way to create an array of a predefined size without also supplying values for the elements of that array     The best way to initialize an array like that is array fill  By far preferable over the various loop-and-insert solutions    my array   array fill 0   size of the array   some data     Every position in the  my array will contain  some data   The first zero in array fill just indicates the index from where the array needs to be filled with the value

User · Answer

PHP Arrays don t need to be declared with a size      An array in PHP is actually an ordered map   You also shouldn t get a warning notice using code like the example you have shown  The common  Notice people get is  Undefined offset  when reading from an array   A way to counter this is to check with isset or array key exists  or to use a function such as   function isset or  array   key   default   NULL        return isset  array  key      array  key     default      So that you can avoid the repeated code   Note  isset returns false if the element in the array is NULL  but has a performance gain over array key exists   If you want to specify an array with a size for performance reasons  look at   SplFixedArray in the Standard PHP Library

User · Answer

Possibly related  if you want to initialize and fill an array with a range of values  use PHP s  wait for it     range function    a   range 1  5       array 1 2 3 4 5   a   range 0  10  2      array 0 2 4 6 8 10

User · Answer

PHP provides two types of array    normal array SplFixedArray   normal array   This array is dynamic   SplFixedArray   this is a standard php library which provides the ability to create array of fix size

User · Answer

array   new SplFixedArray 5      echo  array- gt getSize     n     You can use  PHP documentation more info check this link https   www php net manual en splfixedarray setsize php

User · Answer

There is also array pad  You can use it like this   data   array pad  data  number of items 0    For initializing with zeros the  number of items positions of the array  data

[php] How to create an empty array in PHP with predefined size?

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