Are PHP Integer indexes the most numeric?

Question

Consider this example

<?php $test = array("00"=>"A","B","C","D","E"); print_r($test); echo "<br>"; echo $test[0]; echo "<br>"; echo $test["0"]; echo "<br>"; echo $test["00"]; echo "<br>"; echo $test[00]; ?> 

Exit

Array ([00] => A [0] => B [1] => C [2] => D [3] => E)

IN

IN

BUT

IN

Q1. Why is $test[0] the same as $test["0"] , while $test[00] not the same as $test["00"]

Q2. If the answer to Q1 is that since 00 = 0 numerical, why does this array have one index as 00 and the other as 0 ?

Q3. If you cannot access $test["00"] using $test[0] , how do you know which index is numeric and which is a string? if both are just numbers

Edit

Based on the answers, there is still another question in my mind. Here comes question 4.

Q4. Why is if(00==0) true and if(07==7) false? (for array indices)

Q5.

 $test = array("00"=>"A","0"=>"B","000"=>"C","0000"=>"D","00000"=>"E"); echo $test[0]; 

Why conclusion B if it is not A ? because this is the first element in the array, at position 0

Answer 1

According to the documentation, one of the "[hellip;] keys will produce [,]]:

A string containing a valid integer will be passed to an integer . For example. the key “8” will actually be stored under 8. On the other hand, “08” will not be selected, since it is not a valid decimal integer.

[ link ]

Answer 2

Q1. Since 00 = 0 is numerically

Q2. Since the index "00" not 00

Try:

 $test=array(00=>"A","B","C","D","E"); print_r($test); /* Array ( [0] => A [1] => B [2] => C [3] => D [4] => E ) */ 

Q3.

 echo gettype("00"); # string echo gettype(00); # integer echo gettype("0"); # string echo gettype(0); # integer 

From the manual: http://php.net/manual/en/language.types.array.php

Lines containing real integers will be passed to an integer type. For example. the key “8” will actually be stored under 8. On the other hand, “08” will not be selected, since it is not a valid decimal integer.

Edited after comment

Q4. I think the OP question is, in fact, why the second and fourth behave differently:

 php > var_dump("00" === 0); bool(false) php > var_dump(00 === 0); bool(true) php > var_dump("08" === 8); bool(false) php > var_dump(08 === 8); bool(false) 

I have no answer yet.

Answer 3

 "anystring" == 0; //true "0000" == 0; //true "0" == 0; //true