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PHP

Jonathan Grieve
MOD
Jonathan Grieve
Treehouse Moderator 91,253 Points
Posted by Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,253 Points

This code outputs "1" to the screen. Why?

<?php

    $flavors = array("Chocolate","Vanilla","Strawberry","Cookie Dough");
    echo strpos( $flavors[strpos($flavors[3],"oo")], "a");

?>

This is a strpos that has 2 layers to it, it seems.

On the one hand,it seems to be searching for characters of oo and a

The oo one makes sense to me as the first instance of the o character appears in the 3rd index of strpos in the second character. so 1 would make sense.

But if $flavors[], is in it's own position, how do we know what position this is in?

Unless Vanilla counts as the second index and therefore is 1 and the a character is at position 1 in that element and therefore outputs as 1?

It's a tricky one. :)

1 Answer

Corey Cramer
Corey Cramer
9,453 Points

When evaluating the code it's easiest to work from the inside towards the outside so it would look like this:

<?php
    // Original Code
    $flavors = array("Chocolate","Vanilla","Strawberry","Cookie Dough");
    echo strpos( $flavors[strpos($flavors[3],"oo")], "a");
?>

<?php
    // Evaluate the interior strpos
    $flavors = array("Chocolate","Vanilla","Strawberry","Cookie Dough");
    echo strpos( $flavors[1], "a"); //$flavors[3] is "Cookie Dough" and "oo" appears as the first index since we always start at 0
?>