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debugging - How do I examine defined constants in PHP?

Hey everyone,

I'm fairly new to PHP and currently trying to debug my code. I've come across a situation where I need to examine the defined constants in PHP. I want to understand what values these constants hold at different points in my script.

Is there any built-in function or method in PHP that can help me achieve this? Or is there any simple technique or approach you could suggest?

Any help or guidance would be greatly appreciated.


All Replies



I totally understand the need to examine defined constants in PHP during the debugging process. Fortunately, there are a few ways you can achieve this.

One approach that has been useful for me is using the `defined()` function. This function allows you to check if a constant is defined and obtain its value. Here's an example:

if (defined('MY_CONSTANT')) {
} else {
echo "MY_CONSTANT is not defined.";

In the code snippet above, `MY_CONSTANT` is the name of the constant you want to examine. The `defined()` function checks if it exists, and if true, you can retrieve its value.

Another way I often use to examine constants is by using a combination of `var_dump()` and `get_defined_constants()`. Here's how you can do it:

$constants = get_defined_constants(true)['user'];

foreach ($constants as $name => $value) {
var_dump($name, $value);

In this example, `get_defined_constants(true)` retrieves all the defined constants, and the `foreach` loop helps you iterate through each constant and display its name and value using `var_dump()`.

These techniques have been helpful for me to examine constants and troubleshoot any issues during development. Give them a try, and I hope it helps you too!

If you have any more queries or need further assistance with PHP, feel free to ask. Happy coding!


Hey there,

When it comes to examining defined constants in PHP, you're in luck! PHP provides a handy function called `get_defined_constants()` that allows you to retrieve an array with all the defined constants and their respective values.

To make use of this function, simply call it and store the returned array in a variable. Here's an example:

$constants = get_defined_constants(true)['user'];


In the code snippet above, `get_defined_constants(true)` returns an array containing all the constants categorized by scope, such as `user`, `internal`, and `other`. By specifying `'user'` as the index, we retrieve only the user-defined constants.

Once you have the array of constants, you can print it using `print_r()` or run a loop to examine each constant individually. This can be particularly useful for debugging purposes or when you need to verify the values of constants during runtime.

I hope this helps you out! Let me know if you have any further questions or need assistance with anything else.

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