How to improve var_dump to display variable name and put variable value in ?

Question

I've been using var_dump() function many times in my scripts to check the actual value and type of the variable. For long time it was enought to make function vardump() witch is defined below:

function vardump($_var){
    echo '<pre>';
    var_dump($_var);
    echo '</pre>';
}

But today I've been using it so many times and places, that I've get confused whitch variable i'm realy checking. So the question is how to determine the name of the value that I'm currently checking?

Answer 1

After all morning search I've found this solution:

/**
 * Functions that will display name of the variable, and it's value, and type
 * 
 * @param type $_var - variable to check
 * @param type $aDefinedVars - Always define it this way: get_defined_vars()
 * @return type
 */
function vardump(&$_var, &$aDefinedVars = null){
    if($aDefinedVars){
         foreach ($aDefinedVars as $k=>$v)
            $aDefinedVars_0[$k] = $v; 
        $iVarSave = $_var; // now I copy the $_var value to ano
        $_var     = md5(time());

        $aDiffKeys = array_keys (array_diff_assoc ($aDefinedVars_0, $aDefinedVars));
        $_var      = $iVarSave;
        $name      = $aDiffKeys[0];
    }else{
        $name = 'variable';
    }

    echo '<pre>';
    echo $name . ': ';
    var_dump($_var);
    echo '</pre>';
}

To get the variable name You have to be sure to use vardump() like below:

vardump($variable_name, get_defined_vars());

get_defined_vars() This function returns a multidimensional array containing a list of all defined variables, be them environment, server or user-defined variables, within the scope that get_defined_vars() is called.

I'll put some more explanation for the code, there are some exotic functions used in it.

/**
 * Functions that will display name of the variable, and it's value, and type
 * 
 * @param type $_var - variable to check
 * @param type $aDefinedVars - Always define it this way: get_defined_vars()
 * @return type
 */
function vardump(&$_var, &$aDefinedVars = null){
    // $aDefinedVars - is array of all defined variables - thanks to get_defined_vars() function
    if($aDefinedVars){
        // loop below is used to make a copy of the table of all defined variables
        foreach ($aDefinedVars as $k=>$v)
            $aDefinedVars_0[$k] = $v; // this is done like that to remove all references to the variables
        $iVarSave = $_var; // now I copy the $_var value to another variable to prevent loosing it
        $_var     = md5(time()); // completly random value
        // and the most tricky line
        $aDiffKeys = array_keys (array_diff_assoc ($aDefinedVars_0, $aDefinedVars));

Becouse I have change the $_var value array $aDefinedVars_0 and $aDefinedVars are identical except only $_var value(NOTE $aDefinedVars_0 don't use reference to the variables so chengin $_var I didn't affect on $aDefinedVars_0).

Now the array_diff_assoc function compares $aDefinedVars_0 (with oryginal values) against $aDefinedVars (with changed $_var value) and returns the difference with is associative array (array that contains only one position $_var name and $_var value).

The array_keys function returns the keys, numeric and string, from the input array (and input array contains only one position the one that I'm looking for).

        $_var      = $iVarSave; // now I can restore old $_var value
        $name      = $aDiffKeys[0]; // name of the $_var is on the first (and the only position) in the $aDiffKeys array
    }else{ // is someone won't use get_defined_vars()
        $name = 'variable';
    }

    echo '<pre>';
    echo $name . ': ';
    var_dump($_var); // it can be changed by print_r($_var);
    echo '</pre>';
}

PS. I'm sorry for my English.

Answer 2

I see many strange scripts all over internet to solve your problem or similar ones...

I think, banally, that the best way to do it is passing the name of the variable, shortened if you want, as a string parameter:

function vardump($_var, $var_name){
echo '<pre> Variable <b>$var_name</b>: ';
var_dump($_var);
echo '</pre>';
}

It's not so fast, but it's a good solution.

Answer 3

Since the argument to vardump could be an expression rather than a variable, this is the closest you can get:

function vardump($_var, $_label){
    echo '<pre>';
    if(!empty($_label)){
      echo $_label . ': ';
    }
    var_dump($_var);
    echo '</pre>';
}

Answer 4

Well i would like to recommend a php class called dump_r. This class display the information in different colors and it is combination of var_vump and print_r. You can find it on the phpclasses.org

Here is the link

Answer 5

You cannot get the variable name as a string. You could use the method descriped in How to get a variable name as a string in PHP? but as mentioned, its not perfect.

I think your best bet is to just add it your self or use globals and pass the var name as a strting

function vardump($_var){
    echo '<pre>';
    var_dump($GLOBALS[$_var]);
    echo '</pre>';
}

vardump("foo");