How to check if multiple array keys exists

Question

I have a variety of arrays that will either contain  story  amp  message   or just   story   How would I check to see if an array contains both story and message   array key exists   only looks for that single key in the array     Is there a way to do this

User · Answer

Surprisingly array keys exist doesn t exist   In the interim that leaves some space to figure out a single line expression for this common task  I m thinking of a shell script or another small program   Note  each of the following solutions use concise       array declaration syntax available in php 5 4    array diff   array keys  if  0     count array diff   story    message           array keys  source            all keys found   else        not all      hat tip to Kim Stacks   This approach is the most brief I ve found  array diff   returns an array of items present in argument 1 not present in argument2  Therefore an empty array indicates all keys were found  In php 5 5 you could simplify 0     count      to be simply empty        array reduce   unset  if  0     count array reduce array keys  source        function  in   key   unset  in array search  key   in     return  in            story    message                    all keys found   else        not all     Harder to read  easy to change  array reduce   uses a callback to iterate over an array to arrive at a value  By feeding the keys we re interested in the  initial value of  in and then removing keys found in source we can expect to end with 0 elements if all keys were found   The construction is easy to modify since the keys we re interested in fit nicely on the bottom line   array filter  amp  in array  if  2     count array filter array keys  source   function  key             return in array  key    story    message                      all keys found   else        not all     Simpler to write than the array reduce solution but slightly tricker to edit  array filter is also an iterative callback that allows you to create a filtered array by returning true  copy item to new array  or false  don t copy  in the callback  The gotchya is that you must change 2 to the number of items you expect    This can be made more durable but verge s on preposterous readability    find     story    message    if  count  find      count array filter array keys  source   function  key  use   find    return in array  key   find               all keys found   else        not all

User · Answer

try this   required   a   b    data   a   gt 1  b   gt 2   if count array intersect  required array keys  data   gt 0         a key or all keys in required exist in data   else        no keys found

User · Answer

colsRequired       quot apple quot    quot orange quot    quot banana quot    quot grapes quot         data               quot apple quot   gt  quot some text quot    quot orange quot   gt  quot some text quot         presentInBoth    array intersect  colsRequired array keys  data         if  count  presentInBoth     count  colsRequired           echo  quot Missing keys    quot    join  quot   quot  array diff  colsRequired  presentInBoth        else         echo  quot All Required cols are present quot

User · Answer

This is the function I wrote for myself to use within a class    lt  php        Check the keys of an array against a list of values  Returns true if all values in the list  is not in the array as a key  Returns false otherwise         param  array Associative array with keys and values     param  mustHaveKeys Array whose values contain the keys that MUST exist in  array     param  amp  missingKeys Array  Pass by reference  An array of the missing keys in  array as string values      return Boolean  Return true only if all the values in  mustHaveKeys appear in  array as keys          function checkIfKeysExist  array   mustHaveKeys   amp  missingKeys   array                 extract the keys of  array as an array          keys   array keys  array              ensure the keys we look for are unique          mustHaveKeys   array unique  mustHaveKeys               missingKeys    mustHaveKeys -  keys            we expect  missingKeys to be empty if all goes well          missingKeys   array diff  mustHaveKeys   keys           return empty  missingKeys            arrayHasStoryAsKey   array  story    gt   some value    some other key    gt   some other value     arrayHasMessageAsKey   array  message    gt   some value    some other key    gt   some other value     arrayHasStoryMessageAsKey   array  story    gt   some value    message    gt   some value   some other key    gt   some other value     arrayHasNone   array  xxx    gt   some value    some other key    gt   some other value      keys   array  story    message    if  checkIfKeysExist  arrayHasStoryAsKey   keys        return false     echo  arrayHasStoryAsKey has all the keys lt br   gt      else       echo  arrayHasStoryAsKey does NOT have all the keys lt br   gt       if  checkIfKeysExist  arrayHasMessageAsKey   keys        return false     echo  arrayHasMessageAsKey has all the keys lt br   gt      else       echo  arrayHasMessageAsKey does NOT have all the keys lt br   gt       if  checkIfKeysExist  arrayHasStoryMessageAsKey   keys        return false     echo  arrayHasStoryMessageAsKey has all the keys lt br   gt      else       echo  arrayHasStoryMessageAsKey does NOT have all the keys lt br   gt       if  checkIfKeysExist  arrayHasNone   keys        return false     echo  arrayHasNone has all the keys lt br   gt      else       echo  arrayHasNone does NOT have all the keys lt br   gt        I am assuming you need to check for multiple keys ALL EXIST in an array  If you are looking for a match of at least one key  let me know so I can provide another function   Codepad here http   codepad viper-7 com AKVPCH

User · Answer

lt  php  function check keys exists  keys str        arr   array          return   false      if  keys str       and  empty  arr             keys   explode       keys str           if  empty  keys                foreach  keys as  key                    return   array key exists  key   arr                   if  return    false                       break                                                      return  return        run demo   key    a b c    array   array  a   gt  aaaa   b   gt  ccc   c   gt  eeeee     var dump  check keys exists  key   array

User · Answer

I am not sure  if it is bad idea but I use very simple foreach loop to check multiple array key      get post attachment source url  image       wp get attachment image src get post thumbnail id  post id    single-post-thumbnail       read exif data  tech info   exif read data  image 0        set require keys  keys   array  Make    Model        run loop to add post metas foreach key foreach   keys as  key   gt   value        if  array key exists  value   tech info                    add update post meta         update post meta  post id  MPC PREFIX    value   tech info  value

User · Answer

myArray   array  key1    gt       key2    gt        keys   array  key1    key2    key3     keyExists   count array intersect  keys  array keys  myArray       Will return true  because there are keys from  keys array in  myArray

User · Answer

This is old and will probably get buried  but this is my attempt   I had an issue similar to  Ryan  In some cases  I needed to only check if at least 1 key was in an array  and in some cases  all needed to be present    So I wrote this function           A key check of an array of keys     param array  keys to check An array of keys to check     param array  array to check The array to check against     param bool  strict Checks that all  keys to check are in  array to check   Default  false     return bool     function array keys exist array  keys to check  array  array to check   strict   false           Results to pass back         results   false          If all keys are expected        if   strict               Strict check                Keys to check count             ktc   count  keys to check              Array to check count             atc   count array intersect  keys to check  array keys  array to check                 Compare all            if   ktc      atc                 results   true                  else              Loose check - to see if some keys exist                Loop through all keys to check            foreach   keys to check as  ktc                   Check if key exists in array to check                if  array key exists  ktc   array to check                      results   true                     We found at least one  break loop                    break                                     return  results      This was a lot easier than having to write multiple    and  amp  amp  blocks

User · Answer

Here is a solution that s scalable  even if you want to check for a large number of keys    lt  php     The values in this arrays contains the names of the indexes  keys      that should exist in the data array  required   array  key1    key2    key3      data   array       key1    gt  10       key2    gt  20       key3    gt  30       key4    gt  40      if  count array intersect key array flip  required    data       count  required            All required keys exist

User · Answer

The above solutions are clever  but very slow  A simple foreach loop with isset is more than twice as fast as the array intersect key solution   function array keys exist  keys   array       foreach  keys as  key           if  array key exists  key   array  return false            return true       344ms vs 768ms for 1000000 iterations

User · Answer

Does this not work   array key exists  story    myarray   amp  amp  array key exists  message    myarray

User · Answer

Hope this helps   function array keys exist  searchForKeys   array     inArray   array           inArrayKeys   array keys  inArray       return count array intersect  searchForKeys   inArrayKeys      count  searchForKeys

User · Answer

If you have something like this    stuff   array     stuff 0    array  story    gt   A story    message    gt   in a bottle     stuff 1    array  story    gt   Foo      You could simply count     foreach   stuff as  value      if  count  value     2           story and message     else          only story         This only works if you know for sure that you ONLY have these array keys  and nothing else   Using array key exists   only supports checking one key at a time  so you will need to check both seperately   foreach   stuff as  value      if  array key exists  story    value   amp  amp  array key exists  message    value           story and message     else          either one or both keys missing         array key exists   returns true if the key is present in the array  but it is a real function and a lot to type  The language construct isset   will almost do the same  except if the tested value is NULL   foreach   stuff as  value      if  isset  value  story     amp  amp  isset  value  message             story and message     else          either one or both keys missing         Additionally isset allows to check multiple variables at once   foreach   stuff as  value      if  isset  value  story     value  message             story and message     else          either one or both keys missing         Now  to optimize the test for stuff that is set  you d better use this  if    foreach   stuff as  value      if  isset  value  story          if  isset  value  message               story and message       else            only story           else          No story - but message not checked

User · Answer

It seems to me  that the easiest method by far would be this    required   array  a   b   c   d      values   array       a    gt   1        b    gt   2       missing   array diff key array flip  required    values     Prints   Array       c    gt  2      d    gt  3     This also allows to check which keys are missing exactly  This might be useful for error handling

User · Answer

I usually use a function to validate my post and it is an answer for this question too so let me post it   to call my function I will use the 2 array like this  validatePost   username    password    any other field      POST     then my function will look like this   function validatePost  requiredFields   post                 validation                foreach  requiredFields as  required   gt   key                        if  array key exists  key   post                                  validation  required        key                                   return  validation          this will output this    required                  username                password                any other field             so what this function does is validate and return all the missing fields of the post request

User · Answer

What about this     isset  arr  key1     arr  key2       only return true if both are not null  if is null  key is not in array

User · Answer

One more possible solution   if   array diff   story    message    array keys  array             OK  all the keys are in  array   else         FAIL  some keys are not

User · Answer

If you only have 2 keys to check  like in the original question   it s probably easy enough to just call array key exists   twice to check if the keys exists   if  array key exists  story    arr   amp  amp  array key exists  message    arr            Both keys exist      However this obviously doesn t scale up well to many keys  In that situation a custom function would help   function array keys exists array  keys  array  arr       return  array diff key array flip  keys    arr

User · Answer

Something as this could be used    Say given this array  array in use2     hay    gt   come    message    gt   no    story    gt   yes      This gives either true or false if story and message is there count array intersect   story    message    array keys  array in use2        2       Note the check against 2  if the values you want to search is different you can change            This solution may not be efficient  but it works       Updates  In one fat function           Like php array key exists  this instead search if  one or more  keys exists in the array     param array  needles - keys to look for in the array     param array  haystack - the  lt b gt Associative lt  b gt  array to search     param bool  all -  Optional  if false then checks if some keys are found     return bool true if the needles are found else false   lt br gt     Note  if hastack is multidimentional only the first layer is checked lt br gt      the needles should  lt b gt not be lt b gt  an associative array else it returns false lt br gt     The array to search must be associative array too else false may be returned     function array keys exists  needles   haystack   all   true         size   count  needles       if  all  return count array intersect  needles  array keys  haystack         size      return  empty array intersect  needles  array keys  haystack          So for example with this    array in use2     hay    gt   come    message    gt   no    story    gt   yes      One of them exists -- gt  true  one or more exists   array keys exists   story    message     array in use2  false     all of them exists -- gt  true  all exists   array keys exists   story    message     array in use2     Hope this helps

User · Answer

I use something like this quite often   wantedKeys     story    message     hasWantedKeys   count array intersect array keys  source    wantedKeys    gt  0   or to find the values for the wanted keys   wantedValues   array intersect key  source  array fill keys  wantedKeys  1

User · Answer

sample data  requiredKeys     key1    key2    key3     arrayToValidate     key1    gt  1   key2    gt  2   key3    gt  3    function keysExist array  requiredKeys  array  arrayToValidate        if   requiredKeys     array keys  arrayToValidate             return true             return false

[php] How to check if multiple array keys exists

array_diff + array_keys

array_reduce + unset

array_filter & in_array

Examples related to php

Examples related to key