Looping Through PHP array, error log saying undefined constant

Question

I have a PHP array $data that looks like this...

Array
(
    [section] => Array
        (
            [345dfg] => Array
                (
                    [test] => Array
                        (
                            [name] => John
                        )
                )
            [567fghj] => Array
                (
                    [test] => Array
                        (
                            [name] => Tom
                        )
                )
        )
    [othersection] => Array
        (
            [result] => 2
        )
)

I am trying to loop through each item in section so am doing this...

foreach ($data[section] as $section) {

    echo $section[test][name];

}

It is working correctly but in my error log I get...

PHP Warning:  Use of undefined constant section- assumed 'section' (this will throw an Error in a future version of PHP)

Where am I going wrong?

you have typo error $data['section'], array index accessible with single or double quotes — Rakesh Jakhar, Apr 18 '19 at 12:13

score 6 · Accepted Answer · edited Apr 18 '19 at 13:03

You need to enclose array keys with a single quote as they are of type string.

So,

foreach ($data[section] as $section) {

Should be

foreach ($data['section'] as $section) {

Otherwise, without $ sign and without a single quote, section is considered as constant.

Possibilities with $data['section']:

1) $section as a Variable: $data[$section]

2) section as a Constant: $data[section]

3) section as a array key (string): $data['section']

It is always a good practice to enclose array keys with single quotes.

As by coincidence if the same constant is defined, the value of that constant may be considered as the array key.

If constant not defined, it will show a warning.

same thing will do in this echo $section["test"]["name"]; – Deepak Tyagi Apr 18 '19 at 12:35 — Deepak Tyagi, Apr 18 '19 at 12:35

Looping Through PHP array, error log saying undefined constant

1 Answers1