{"id":760,"date":"2021-03-27T02:37:21","date_gmt":"2021-03-27T02:37:21","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=760"},"modified":"2025-04-05T14:11:55","modified_gmt":"2025-04-05T14:11:55","slug":"php-var_dump","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-var_dump\/","title":{"rendered":"PHP var_dump"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to use the PHP var_dump()<\/code> function to dump the information about a variable.<\/p>\n\n\n\n

Introduction to the PHP var_dump function #<\/a><\/h2>\n\n\n\n

The var_dump()<\/code> is a built-in function<\/a> that allows you to dump the information about a variable<\/a>. The var_dump()<\/code> function accepts a variable and displays its type and value.<\/p>\n\n\n\n

Suppose that you have a variable called $balance<\/code> with a value of 100<\/code>:<\/p>\n\n\n

<?php<\/span>\n\n$balance = 100<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
To display the information of the $balance<\/code> variable, you place it within parentheses that follow the var_dump<\/code> function name like this:<\/p>\n\n\n
<?php<\/span>\n\n$balance = 100<\/span>;\nvar_dump($balance);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
If you open the page on the web browser, you’ll see the following output:<\/p>\n\n\n
int(100<\/span>)<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The following shows how to dump information about two variables $amount<\/code> and $message<\/code>:<\/p>\n\n\n
<?php<\/span>\n\n$balance = 100<\/span>;\n$message = 'Insufficient balance'<\/span>;\n\nvar_dump($balance);\nvar_dump($message);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
int(100<\/span>) string(20<\/span>) \"Insufficient balance\"<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
To make the output more intuitive, you can wrap the output of the var_dump()<\/code> function in a pre<\/code> tag like this:<\/p>\n\n\n
<?php<\/span>\n\n$balance = 100<\/span>;\n\necho<\/span> '<pre>'<\/span>;\nvar_dump($balance);\necho<\/span> '<\/pre>'<\/span>;\n\n$message = 'Insufficient balance'<\/span>;\n\necho<\/span> '<pre>'<\/span>;\nvar_dump($message);\necho<\/span> '<\/pre>'<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
int(100<\/span>)\nstring(20<\/span>) \"Insufficient balance\"<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The output now is much more readable.<\/p>\n\n\n\n
The dump helper function #<\/a><\/h2>\n\n\n\n
It’s tedious to always echo the opening <pre><\/code> and closing <\/pre><\/code> tags when you dump the information about the variable.<\/p>\n\n\n\n
To make it easier, you can define a function<\/a> and reuse it. For now, you can think that a function is a reusable piece of code that can be referenced by a name. A function may have input and also output.<\/p>\n\n\n\n
PHP has many built-in functions like var_dump()<\/code>. It also allows you to define your own functions. These functions are called user-defined functions<\/strong>. And you’ll learn more about it in the function tutorial<\/a>.<\/p>\n\n\n\n
The following defines a function called d()<\/code> that accepts a variable. It shows the information about the variable and wraps the output in the <pre> tag:<\/p>\n\n\n
<?php<\/span>\nfunction<\/span> d<\/span>($data)<\/span>\n<\/span>{\n\techo<\/span> '<pre>'<\/span>;\n\tvar_dump($data);\n\techo<\/span> '<\/pre>'<\/span>;\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
To use the d()<\/code> function, you can pass a variable to it as follows:<\/p>\n\n\n
<?php<\/span>\nfunction<\/span> d<\/span>($data)<\/span>\n<\/span>{\n\techo<\/span> '<pre>'<\/span>;\n\tvar_dump($data);\n\techo<\/span> '<\/pre>'<\/span>;\n}\n\n\n$balance = 100<\/span>;\nd($balance );\n\n$message = 'Insufficient balance'<\/span>;\nd($message);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
int(100<\/span>)\nstring(20<\/span>) \"Insufficient balance\"<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The output is much cleaner now.<\/p>\n\n\n\n
Dump and die using the var_dump() and die() functions #<\/a><\/h2>\n\n\n\n
The die()<\/code> function displays a message and terminates the execution of the script:<\/p>\n\n\n
die<\/span>($status);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Sometimes, you want to dump the information of a variable and terminate the script immediately. In this case, you can combine the var_dump()<\/code> function with the die()<\/code> function as follows:<\/p>\n\n\n
<?php<\/span>\n\n$message = 'Dump and die example'<\/span>;\n\necho<\/span> '<pre>'<\/span>;\nvar_dump($message);\necho<\/span> '<\/pre>'<\/span>;\ndie<\/span>();\n\necho<\/span> 'After calling the die function'<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
string(20<\/span>) \"Dump and die example\"<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
How it works<\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
The output shows the variable’s value (100) and its type (int<\/a>) which stands for integer.<\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n