Xdebug和用于notepad++的DBGp插件用于繁重的bug查找，FirePHP用于轻量级的东西。又快又脏?没有什么比dBug更好的了。

1)使用print_r()。在TextMate中，我有一个'pre'的片段，它扩展为:

echo "<pre>";
print_r();
echo "</pre>";

2)我使用Xdebug，但还不能让GUI在我的Mac上正常工作。它至少打印出一个可读的堆栈跟踪版本。

Nusphere也是一个很好的php调试器 nusphere

Xdebug和用于notepad++的DBGp插件用于繁重的bug查找，FirePHP用于轻量级的东西。又快又脏?没有什么比dBug更好的了。

我使用Netbeans的XDebug和Easy XDebug FireFox插件

The add-on is essential when you debug MVC projects, because the normal way XDebug runs in Netbeans is to register the dbug session via the url. With the add-on installed in FireFox, you would set your Netbeans project properties -> Run Configuratuion -> Advanced and select "Do Not Open Web Browser" You can now set your break points and start the debugging session with Ctrl-F5 as usual. Open FireFox and right-click the Add-on icon in the right bottom corner to start monitoring for breakpoints. When the code reaches the breakpoint it will stop and you can inspect your variable states and call-stack.

For the really gritty problems that would be too time consuming to use print_r/echo to figure out I use my IDE's (PhpEd) debugging feature. Unlike other IDEs I've used, PhpEd requires pretty much no setup. the only reason I don't use it for any problems I encounter is that it's painfully slow. I'm not sure that slowness is specific to PhpEd or any php debugger. PhpEd is not free but I believe it uses one of the open-source debuggers (like XDebug previously mentioned) anyway. The benefit with PhpEd, again, is that it requires no setup which I have found really pretty tedious in the past.