How do I declare a two dimensional array

Question

What s the easiest way to create a 2d array  I was hoping to be able to do something similar to this   declare int d 0  m  0  n

User · Answer

For a simple   fill as you go  kind of solution    foo   array array      This will get you a flexible pseudo two dimensional array that can hold  foo n  n  where n  lt   8  of course your limited by the usual constraints of memory size  but you get the idea I hope   This could  in theory  be extended to create as many sub arrays as you need

User · Answer

Or for larger arrays  all with the same value    m by n array   array fill 0   n  array fill 0   m   value     will create an  m by  n array with everything set to  value

User · Answer

Firstly  PHP doesn t have multi-dimensional arrays  it has arrays of arrays   Secondly  you can write a function that will do it   function declare  m   n   value   0      return array fill 0   m  array fill 0   n   value

User · Answer

atli s answer really helped me understand this   Here is an example of how to iterate through a two-dimensional array    This sample shows how to find values for known names of an array and also a foreach where you just go through all of the fields you find there    I hope it helps someone    array   array      0   gt  array           name    gt   John Doe            email    gt   john example com             1   gt  array           name    gt   Jane Doe            email    gt   jane example com             foreach    array  as  groupid   gt   fields        echo  hi element     groupid     n       echo    name is     fields  name       n       echo    email is     fields  email       n        i   0      foreach   fields as  field             echo    field  i is    field     n            i              Outputs   hi element 0   name is John Doe   email is john example com   field 0 is John Doe   field 1 is john example com hi element 1   name is Jane Doe   email is jane example com   field 0 is Jane Doe   field 1 is jane example com

User · Answer

The following are equivalent and result in a two dimensional array    array   array      array 0  1  2       array 3  4  5        or   array   array      array     array 0  1  2    array     array 3  4  5

User · Answer

You need to declare an array in another array    arr   array array content   array content     Example    arr   array array 1 2 3   array 4 5 6     To get the first item from the array  you ll use  arr 0  0   that s like the first item from the first array from the array   arr 1  0  will return the first item from the second array from the array

User · Answer

And for me the argument about whether an array should be sparse or not depends on the context   For example  if  a 6  9  is not populated is the equivalent to  a 6  9  being populated with for example with    or 0

User · Answer

r   array  arr1   arr2      to echo a single array element you should write   echo  r 0   echo  r 1     output would be  arr1 arr2

User · Answer

And I like this way    cars   array       array  Volvo  22     array  BMW  15     array  Saab  5     array  Land Rover  17

User · Answer

As far as I m aware there is no built in php function to do this  you need to do it via a  loop or via a custom method that recursively calls to something like array fill inidcated in the answer by  Amber   I m assuming you mean created an empty but intialized array of arrays   For example  you want a final results like the below of a array of 3 arrays       final array   array array    array    array       This is simple to just hand code  but for an arbitrary sized array like a an array of 3 arrays of 3 arrays it starts getting complex to initialize prior to use         final array   array array array    array    array     array array    array    array     array array    array    array           etc     I get the frustration  It would be nice to have an easy way to declare an initialized array of arrays any depth to use without checking or throwing errors

User · Answer

You can try this  but second dimension values will be equals to indexes    array   array fill keys range 0 5   range 0 5     a little more complicated for empty array    array   array fill keys range 0  5   array fill keys range 0  5   null

User · Answer

If you want to quickly create multidimensional array for simple value using one liner I would recommend using this array library to do it like this    array   Arr  setNestedElement      1 2 3    value      which will produce      1   gt        2   gt          3   gt   value

User · Answer

Just declare  You don t have to  Just make sure variable exists    d   array      Arrays are resized dynamically  and attempt to write anything to non-exsistant element creates it  and creates entire array if needed    d 1  2    3    This is valid for any number of dimensions without prior declarations

User · Answer

You can also create an associative array  or a  hash-table  like array  by specifying the index of the array    array   array      0   gt  array           name    gt   John Doe            email    gt   john example com             1   gt  array           name    gt   Jane Doe            email    gt   jane example com              Which is equivalent to   array   array      array 0    array     array 0   name      John Doe    array 0   email      john example com     array 1    array     array 1   name      Jane Doe    array 1   email      jane example com

[php] How do I declare a two dimensional array?

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