Re: How to print variable name and contents

From: Date: Fri, 17 Jun 2005 14:18:51 +0000
Subject: Re: How to print variable name and contents
References: 1  Groups: php.general 
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nntp.charter.net wrote:
I want to write a trace procedure and call it with variable names, and I am having trouble with the syntax. My goal is to have a procedure that will echo lines such as: Trace: $myvar="the contents of $myvar My attempt that didn't work is to write a function: function my_trace($m){ echo ("\n<br>TRACE: $m = "); eval("\$t=\"$m\";"); echo($t."<br>\n"); } and call it with statements like: my_trace("\$my_var"); my_trace("\$_ENV[\"COMPUTERNAME\"]"); What am I doing wrong, and how should this be done? Also, should I post to a different group? Thanks, Gil Grodsky ggrodsky@charter.net
Try this script, it works for me: $my_var = 'Hello world!';
function my_trace($m){                   // pay attention to the use of single vs double quotes throughout
$q = substr($m, 1);                   // chop off the leading '$' in the variable name
@eval("global \${$q};");              // need to use global to get value of local variables into this function
                                    // also need @ to supress warning caused by brackets in superglobal variables
eval("\$t = \${$q};");                // assign value of orginal $m to $t
echo ("<br />TRACE: $m = $t<br />");  // output 
my_trace('$my_var');                     // note the use of single quotes here
my_trace('$_ENV["COMPUTERNAME"]');       // note where the single quotes are used here
Hope it helps, Bob

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