Creating arrays in a for loop via list()?

Question

$$I have a bunch fo text files I'd like to eventually explode into arrays, but since the amount of text files is dynamically chosen via user input, I can't just initialize them one-by-one and instead am opting for a for loop.

For the sake of example, three text files I have contain the following (excuse the \n, imagine it's a line break):

file1.txt = 1 \n 2 \n 3

file2.txt = 6 \n 2 \n 7

file3.txt = 9 \n 1 \n 9

The code I attempted:

<?php
    for ($i = 1; $i <= 3; $i++) {
        list($line1[$i], $line2[$i], $line3[$i]) = file("public_html/texts/file".$i.".txt");
?>

This obviously doesn't work, but I'm not sure why. In the end, the result should be:

$line1[1] = 1
$line2[1] = 2
$line3[1] = 3
$line1[2] = 6
$line2[2] = 2
$line3[2] = 7
$line1[3] = 9
$line2[3] = 1
$line3[3] = 9

How do I go about doing this?

edit; fixed typo.

Your code seems right, the error must be elsewhere not your use of list(). Have you checked the file is correctly read and returned by file() ? — Nelson Benítez León
– Nelson Benítez León, Commented Nov 2, 2012 at 8:59

Nelson Benítez León · Accepted Answer · 2012-11-02 08:53:20Z

2

You have an error in your code, see:

file("public_html/texts/file".&i.".txt");
                              ^-- TYPO HERE

answered Nov 2, 2012 at 8:53

Nelson Benítez León

51.1k8 gold badges70 silver badges84 bronze badges

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

2 Comments

Nelson Benítez León Over a year ago

See my comment to your question above, your error should be elsewhere, you seem to be running php with no error logging, otherwise the above typo would cause a PHP parse error that you would have seen. So first enable php error output so you see the errors in your code.

gator Over a year ago

Thank you for the help, I really appreciate it. I do have error logging, and the error I get in WAMP is that any var I try to echo doesn't exist. When I echo say, $line1[1], it says it is undefined.

Mihai Matei · Accepted Answer · 2012-11-02 09:10:25Z

1

for($i = 1; $i <= 3; $i++) {

    $lines = file('public_html/texts/file' . $i . '.txt');

    $line1[] = $lines[0];
    $line2[] = $lines[1];
    $line3[] = $lines[2];
}

edited Nov 2, 2012 at 9:10

answered Nov 2, 2012 at 8:52

Mihai Matei

24.3k5 gold badges34 silver badges50 bronze badges

1 Comment

gator Over a year ago

I'm sorry, I don't really see it here. This takes into consideration only file1.txt and file2.txt, but the amount of text files is user defined and can be any number.

Collectives™ on Stack Overflow

Creating arrays in a for loop via list()?

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related