Undefined Offset when trying to loop through array

Question

I need to convert my array:

$tdata = array(11,3,8,12,5,1,9,13,5,7);

Into a string like this:

11-3-8-12-5-1-9-13-5-7

I was able to get it work with:

$i = 0;
$predata = $tdata[0];
foreach ($tdata as $value)
{
    $i++;
    if ($i == 10) {break;}
    $predata.='-'.$tdata[$i];

}

But was wondering if there is an easier way?

I tried something like:

$predata = $tdata[0];

foreach ($tdata as $value)
{
    if($value !== 0) {
        $predata.= '-'.$tdata[$value];
    }
}

but it result in bunch of Undefined Offset errors and incorrect $predata at the end.

So I want to learn once and for all:

How to loop through the entire array starting from index 1 (while excluding index 0)?
Is there a better approach to convert array into string in the fashion described above?

Kevin · Accepted Answer · 2014-10-22 03:40:05Z

6

Yes there is a better approach to this task. Use implode():

$tdata = array(11,3,8,12,5,1,9,13,5,7);
echo implode('-', $tdata); // this glues all the elements with that particular string.

To answer question #1, You could use a loop and do this:

$tdata = array(11,3,8,12,5,1,9,13,5,7);
$out = '';
foreach ($tdata as $index => $value) { // $value is a copy of each element inside `$tdata`
// $index is that "key" paired to the value on that element
    if($index != 0) { // if index is zero, skip it
        $out .= $value . '-';
    }
}
// This will result into an extra hypen, you could right trim it

echo rtrim($out, '-');

edited Oct 22, 2014 at 3:40

answered Oct 22, 2014 at 3:32

Kevin

41.9k12 gold badges57 silver badges72 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Acidon Over a year ago

What???? So simple???? I was going crazy with those loops when there was a one string solution all along... THANK YOU!

Kevin Over a year ago

@Acidon yes there is a built in function in PHP that already does this :) . Glad i was able to help

Acidon Over a year ago

ahh, thanks for the answer for 1st question as well, you are the man! Using trim is brilliant and would work for my case as well :) God, I love PHP!

Collectives™ on Stack Overflow

Undefined Offset when trying to loop through array

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related