Multiple inputs with same name through POST in php

Question

Is it possible to get multiple inputs of the same name to post and then access them from PHP? The idea is this: I have a form that allows the entry of an indefinite number of physical addresses along with other information. If I simply gave each of those fields the same name across several entries and submitted that data through post, would PHP be able to access it?

Say, for example, I have five input on one page named "xyz" and I want to access them using PHP. Could I do something like:

    $_POST['xyz'][0]

If so, that would make my life ten times easier, as I could send an indefinite amount of information through a form and get it processed by the server simply by looping through the array of items with the name "xyz".

Solution 1

Change the names of your inputs:

<input name="xyz[]" value="Lorem" />
<input name="xyz[]" value="ipsum"  />
<input name="xyz[]" value="dolor" />
<input name="xyz[]" value="sit" />
<input name="xyz[]" value="amet" />

Then:

$_POST['xyz'][0] == 'Lorem'
$_POST['xyz'][4] == 'amet'

---

If so, that would make my life ten times easier, as I could send an indefinite amount of information through a form and get it processed by the server simply by looping through the array of items with the name "xyz".

Note that this is probably the wrong solution. Obviously, it depends on the data you are sending.

Solution 2

In your html you can pass in an array for the name i.e

<input type="text" name="address[]" /> 

This way php will receive an array of addresses.

Solution 3

Eric answer is correct, but the problem is the fields are not grouped. Imagine you have multiple streets and cities which belong together:

<h1>First Address</h1>
<input name="street[]" value="Hauptstr" />
<input name="city[]" value="Berlin"  />

<h2>Second Address</h2>
<input name="street[]" value="Wallstreet" />
<input name="city[]" value="New York" />

The outcome would be

$POST = [ 'street' => [ 'Hauptstr', 'Wallstreet'], 
          'city' => [ 'Berlin' , 'New York'] ];

To group them by address, I would rather recommend to use what Eric also mentioned in the comment section:

<h1>First Address</h1>
<input name="address[1][street]" value="Hauptstr" />
<input name="address[1][city]" value="Berlin"  />

<h2>Second Address</h2>
<input name="address[2][street]" value="Wallstreet" />
<input name="address[2][city]" value="New York" />

The outcome would be

$POST = [ 'address' => [ 
                 1 => ['street' => 'Hauptstr', 'city' => 'Berlin'],
                 2 => ['street' => 'Wallstreet', 'city' => 'New York'],
              ]
        ]

Comments

[Adam]

Thanks for the help. Since this is the most complete answer to my question, I choose it as THE answer. However, the answer from Interstellar_coder is good as well, but you've explained that this can potentially be a pitfall if used incorrectly. I will be limiting the maximum number of items and I will be doing a lot of validation on this form, so I shouldn't run into any security issues unless there are issues inherent in this approach which have not been explained here.

[Eric]

@Adam: Having reread your question, this is a perfectly accetable approach. You might want to go one stage further, and have address[0][street] address[0][city] address[0][zip], address[1][street] address[1][city] address[1][zip] ... You can read these with $_POST['address'][0]['city'], for instance

[Adam]

How would this then be named inside HTML? That would potentially ease the difficulty by quite a lot. The approach I was going to take is have several fields named like so: l1[], l2[], city[], state[], zip[], zip4[]. Then, for the first address, I simply use $i == 0 in each field. So if I understand your approach correctly, I would probably name my elements like so: name="address[][city]" for a city field. Is that correct?

[Adam]

Good and correct answer, which is why I voted it up. You didn't explain much about it though, which is why I didn't select it as the answer to my question. This helps me a ton, as I've been trying to figure this one out for a while (as you may notice in one of my previous questions). My previous approach was to simply add all of the inputs to hidden fields with * separated values and resetting the input fields, but this approach is ten times better as I will be able to allow the deletion of previously added addresses if it is discovered they are incorrect.

[Eric]

@Adam: Possibly. I think you might need to place the index inside the first [] though, such as [0]. That makes the HTML harder to generate, but the data is no harder to read PHP-side

[rajeev]

Question coming to my mind here is: whether the field will go in random order inside the array? or will they be in order in which they are laid out in form (even if some fields are left empty)?

[user2799603]

I tried this solution in my webpage, but the values "Lorem", "ipsum" will show up on the webpage. I want to hide these values and treat them as IDs, not displayed text. Any suggestions?

[ashishkumar148]

how to handle this type of thing in angularjs. e.g. stackoverflow.com/questions/29415774/…

[tashi]

Input type email and file are only supported for multiple value with same name. I failed to achieve multiple values.

[Fi Horan]

Just be careful to remember that an empty array will have a count of 1 having been POST'ed with nothing at the '0' index. You'll need to check by using the 'empty' keyword if(!empty($arrayName)){//do something}

[Javid]

This is nonsense to parse it yourself. There's no scenario that this would be needed.

[Mahsa]

Any idea about how can I get access to the old value of these fields when the form is validated and return the error?

[Nico Haase]

Please share more details. How does this answer the given question? You don't even reference how this helps to use "an indefinite number of physical addresses"