如何使用数组的值来填充另一个数组的键？

I have an array of field names. I would like to use those to populate the keys of another array, which will have empty values as default. Is there a single command I can do this with?

As of PHP 5.2.0 you can also use array_fill_keys

array_fill_keys( array('foo', 'bar', 'baz'), NULL);

which will give

Array
(
    [foo] => 
    [bar] => 
    [baz] => 
)

Try the array_combine and array_fill functions:

array_combine($arrayOfKeys, array_fill(0, count($arrayOfKeys), null))

Or, as array_fill is only available since PHP 4.2, try array_pad instead:

array_combine($arrayOfKeys, array_pad(array(), count($arrayOfKeys), null))

If I understand your question, you need array_combine()