Sort array items in PHP so that it is not case sensitive to letters

问题

When I use sort($topics) I get something along the lines of:

1. Apple
2. Green
3. Zebra
4. grass

In this example, "grass" starts with a lower case g but ends up after "Zebra" which has a capital letter.

How do I make it so that it sorts it where it ignores whether the word starts with capitals or not?

1. Apple
2. Green
3. grass
4. Zebra

回答1:

Call usort() as usort($topics, 'strnatcasecmp').

strcasecmp would do the job, too, but strnatcasecmp will also sort properly when you have numbers in your string.

回答2:

There is natcasesort .

natcasesort($topics);

来源：https://stackoverflow.com/questions/7763936/sort-array-items-in-php-so-that-it-is-not-case-sensitive-to-letters