This is a code snippet of PHP about how to get the variable name.

how_to_get_variable_name.php

<?php
// ref: http://mach13.com/how-to-get-a-variable-name-as-a-string-in-php

$var = "hello, taiwan";

$name   = var_name($var, get_defined_vars());
$val    = $var;

echo $name; // var
echo $val;  // hello, taiwan


function var_name (&$iVar, &$aDefinedVars)
{
    foreach ($aDefinedVars as $k=>$v)
        $aDefinedVars_0[$k] = $v;

    $iVarSave = $iVar;
    $iVar     =!$iVar;

    $aDiffKeys = array_keys (array_diff_assoc ($aDefinedVars_0, $aDefinedVars));
    $iVar      = $iVarSave;

    return $aDiffKeys[0];
}