Get the index of a certain value in an array in PHP

Question

I have an array    list   array  string1    string2    string3      I want to get the index for a given value  i e  1 for string2 and 2 for string3   All I want is the position of the strings in the array   string1 is 0 string2 is 1 string3 is 2   How to achieve this

User · Answer

Could you be a little more specific    key   array search  string2   list    works fine for me   Are you trying to accomplish something more complex

User · Answer

You ll have to create a function for this  I don t think there is any built-in function for that purpose  All PHP arrays are associative by default  So  if you are unsure about their keys  here is the code     lt  php   given array   array  Monday    gt   boring    Friday    gt   yay    boring    Sunday    gt   fun   7   gt   boring    Saturday    gt   yay fun    Wednesday    gt   boring    my life    gt   boring      repeating value    boring    function array value positions  array   value        index   0       value array   array            foreach  array as  v               if  value     v                    value array  index     value                         index                  return  value array      value array   array value positions  given array   repeating value     result    The value   value array 0   was found at these indices in the given array       key string   implode      array keys  value array     echo  result    key string     n    Output  The value  boring  was found at these indices in the given array  0  2  4  6  7

User · Answer

This code should do the same as your new routine  working with the correct multi-dimensional array      arr   array     string1    gt  array  a    gt       b    gt       c    gt          string2    gt  array  a    gt       b    gt       c    gt          string3    gt  array  a    gt       b    gt       c    gt            echo  Index of  string2       array search  string2   array keys  arr

User · Answer

Other folks have suggested array search   which gives the key of the array element where the value is found   You can ensure that the array keys are contiguous integers by using array values      list   array 0  gt  string1    foo   gt  string2   42  gt  string3     index   array search  string2   array values  list    print   index n       result  1   You said in your question that array search   was no use   Can you explain why   What did you try and how did it not meet your needs

User · Answer

Here is a function that will work for numeric or string indices  Pass the array as first parameter  then the index to the element that needs to be moved and finally set the direction to -1 to move the element up and to 1 to move it down  Example  Move   first   gt  Peter   second   gt  Paul   third   gt  Kate    second  -1  will move Paul up and Peter down  function Move  a  element  direction      temp        index   0   foreach  a as  key  gt  value         temp  index       key      index   array search  element  temp     newpos    index  direction   if isset  temp  newpos               value2    temp  newpos            temp  newpos   element           temp  index   value2    else         move is not possible     return  a    returns the array unchanged        final        foreach  temp as  next         final  next   a  next      return  final

User · Answer

The problem is that you don t have a numerical index on your array  Using array values   will create a zero indexed array that you can then search using array search   bypassing the need to use a for loop   list     string1    string2    string3     index   array search  string2  array values  list

User · Answer

If you re only doing a few of them  and or the array size is large   then you were on the right track with array search    list   array  string1    string2    string3     k   array search  string2    list      k   1    If you want all  or a lot of them   a loop will prob do you better   foreach   list as  key   gt   value        echo  value     in      key              Prints  string1 in 0  string2 in 1  string3 in 2

User · Answer

find  Topsite    list array  Tope   Ajayi   Topsite   Infotech     list count count  list   sort  list   for  i 0  i lt  list count  i          if  list  i    find             position  i           echo  position

User · Answer

or considering your array structure    array   array     string1    gt  array  a    gt       b    gt       c    gt          string2    gt  array  a    gt       b    gt       c    gt          string3    gt  array  a    gt       b    gt       c    gt               you could just  function findIndexOfKey  key to index  array     return array search  key to index array keys  array           executed  print   r n  -- Method 1 --   r n   print   index of  string1     findIndexofKey  string1   array    r n   print   index of  string2     findIndexofKey  string2   array    r n   print   index of  string3     findIndexofKey  string3   array    r n        alternatively  print   r n  -- Method 2 --   r n   print   index of  string1     array search  string1  array keys  array     r n   print   index of  string2     array search  string2  array keys  array     r n   print   index of  string3     array search  string3  array keys  array     r n        recursersively  print   r n  -- Method 3 --   r n   foreach array keys  array  as  key   gt   value     print   index of     value        key   r n          outputs    -- Method 1 --    index of  string1   0  index of  string2   1  index of  string3   2    -- Method 2 --    index of  string1   0  index of  string2   1  index of  string3   2    -- Method 3 --    index of  string1   0  index of  string2   1  index of  string3   2

User · Answer

array search is the way to do it      array search   mixed  needle   array  haystack    bool  strict   FALSE       mixed   From the docs    array   array 0   gt   blue   1   gt   red   2   gt   green   3   gt   red      key   array search  green    array       key   2   key   array search  red    array         key   1    You could loop over the array manually and find the index but why do it when there s a function for that  This function always returns a key and it will work well with associative and normal arrays

User · Answer

array search should work fine  just tested this and it returns the keys as expected    list   array  string1    string2    string3    echo  Key     array search  string1    list   echo   Key     array search  string2    list   echo   Key     array search  string3    list     Or for the index  you could use   list   array  string1    string2    string3    echo  Index     array search  string1   array merge  list    echo   Index     array search  string2   array merge  list    echo   Index     array search  string3   array merge  list

User · Answer

Try the array keys PHP function    key string1   array keys  list   string1

[php] Get the index of a certain value in an array in PHP

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