Create array from submitted values - html

Question

How do I create 2 HTML arrays from value pairs on form submit?
from <input type="text" name="val_a1" value="1">
to <input type="text" name="val_b1" value="2">
from <input type="text" name="val_b1" value="3">
to <input type="text" name="val_b1" value="4">
from <input type="text" name="val_c1" value="5">
to <input type="text" name="val_c1" value="6">
to look like
array[1,3,5] and array[2,4,6]
Do I need to five unique field names, like in my example or just keep val_a and val_b?

Answer 1

Use brackets in the field names to have the input value return an array:
from <input type="text" name="from[0]" value="1">
to <input type="text" name="to[0]" value="2">
from <input type="text" name="from[1]" value="3">
to <input type="text" name="to[1]" value="4">
from <input type="text" name="from[2]" value="5">
to <input type="text" name="to[2]" value="6">
Note that the keys (0, 1, 2) are optional and could be anything you want (or none at all), but I used them so it would make more sense once you get the return values. You should receive from and to as an array when submitting the form now.

Answer 2

AFAIK you can have several query values with the same name. So it would then depend on what backend you are using to parse the querystring. Common practice is to name several fields that should be grouped together name[], and most backends will turn that into an array then. So try both methods out on your backend and check how they are treated!

Answer 3

if you just want an array you can do it like this
from <input type="text" name="from[]" value="1">
to <input type="text" name="to[]" value="2">
from <input type="text" name="from[]" value="3">
to <input type="text" name="to[]" value="4">
from <input type="text" name="from[]" value="5">
to <input type="text" name="to[]" value="6">
you don't need to number them they will be in order they are recieved
but you can go into nesting too see this post for more details