There is an array

array (
  [47] = & gt; Array (
    [PageName] = & gt; Basic version
    [PageMeta] = & gt; Main.
    [betaid] = & gt;
  )
)

I want to get his key “47”, how to do it? The simplest checking on the value does not work

if (in_array ("Main", $ pages)) ECHO 123;

Answer 1

Search options.

by key:

reset ($ pages);
$ firstKey = Key ($ pages);
if (in_array ('Main', $ Pages [$ firstkey])) {
  // Found 'Main' ...
} else {
  // Didn't find 'Main' ...
}

Passage by array:

foreach ($ pages as $ key = & gt; $ value)
{
  If (in_array ('Main', $ Value)) {
    // Found 'Main' ...
  } else {
    // Didn't find 'Main' ...
  }
}

A more versatile method for checking values, suitable for nested arrays:

function check ($ array, $ value)
{
  Foreach ($ Array AS $ Key = & GT; $ inner) {
    If (IS_Array ($ Inner)) {
      if (check ($ inner, $ value)) {
        RETURN TRUE;
      }
    } else {
      if ($ value == $ inner) {
        RETURN TRUE;
      }
    }
  }
  RETURN FALSE;
}

Usage:

if (check ($ pages, 'main')) {
   // Found 'Main' ...
} else {
   // Didn't find 'Main' ...
}

Answer 2

You are looking for an array in the upper level, it will not work like that. And so it should:

foreach ($ pages as $ k = & gt; $ v) {
  if (in_array ("Main", $ V)) {
    Echo $ k;
    Break;
}