I'm wondering if all PHP arrays have to have keys for their values? I don't think they do, and so my next question is, does the key for each value automatically become it's position in the array (0-based indexing), or else does the value itself become the key?
Perhaps the value simply doesn't have a key... curious, because I can't delete an element from an array inside a foreach loop if it doesn't have a key.
分享 I'm wondering if all PHP arrays have to have keys for their values?
Yes, they do.
Does the key for each value automatically become it's position in the array (0-based indexing)
Yes. If you do not explicitly specify a key value, then it's corresponding position will be used (0-based indices).
I can't delete an element from an array inside a foreach loop if it doesn't have a key.
You don't always need a key to operate with arrays. Also, foreach construct allows you to use the keys inside the array: foreach ($iterable as $key => $value).
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