Hi, thanks for the PR, but that's not a bug. Not displayed indices are increasing numbers from the last explicit index. That matches how PHP indices work.

How do you propose to solve it then? Scanning the whole array and checking whether indices are sequence or not doesn't sound very performance sensitive to me. Especially for larger arrays.

I propose to close as this output is expected.

For array[100 => true, 101 => true] is not expected output[100 => true, true]

To me it is, and the code matches :)
Seehttps://3v4l.org/CXXvn

Got it. I'll show you my use case:

Consider this array:

[20 =>true,21 =>true,5 =>true,3 =>true,80 =>true,81 =>true,82 =>true,120 =>true,150 =>true,1 =>true,9 =>true,10 =>true,60 =>true,61 =>true,62 =>true,8 =>true,50 =>true,51 =>true,100 =>true,]

Current version of VarExporter produces this:

[20 =>true,true,5 =>true,3 =>true,80 =>true,true,true,120 =>true,150 =>true,1 =>true,9 =>true,true,60 =>true,true,true,8 =>true,50 =>true,true,100 =>true,]

And that gives this when php array is hydrated from VarExporter's output:

[20 =>true,21 =>true,5 =>true,3 =>true,80 =>true,81 =>true,82 =>true,120 =>true,150 =>true,1 =>true,9 =>true,151 =>true,60 =>true,152 =>true,153 =>true,8 =>true,50 =>true,154 =>true,100 =>true,]

You can see it's not the same array as the origin

[     20 => true,     21 => true,     5 => true,     3 => true,     80 => true,     81 => true,     82 => true,     120 => true,     150 => true,     1 => true,     9 => true,-    10 => true,+    151 => true,     60 => true,-    61 => true,-    62 => true,+    152 => true,+    153 => true,     8 => true,     50 => true,-    51 => true,+    154 => true,     100 => true, ];

Happy new year everyone! 🎉 IMO we only need to improve the dump to take into account whether or not the currently exported index is greater than the greatest one (see#29741 for my suggestion to fix this).