This function will resolve objects to their class name, resources to their resource type name, and scalar values to their common name as would be used in type ...

Returns the type of the PHP variable value . For type checking, use is_* functions. Parameters ¶. value. The variable being type checked.

PHP Manual ¶ · Basic syntax · Types · Variables · Constants · Expressions · Operators · Control Structures · Functions ...

PHP Manual - Manual · Language Reference · Function Reference · Hiding PHP

For me, just outputting variables only works when I know a method should be broken. I use Xdebug in PHP Storm (available on other IDE's and editors as well)

Simple function to get a string in form "filename ... debug backtrace in readable format (i.e. your error handling function) <?php ... My PHP.net · Contact · Other ...

image_type_to_extension - Get file extension for image type ... SolrClient::getDebug - Returns the debug data for the last connection attempt ... Other PHP.net ...

This function displays structured information about one or more expressions that includes its type and value. Arrays and objects are explored recursively ...

Var_export · Print_r · Var_dump

Function Reference ¶ · Arrays · Classes/Objects — Class/Object Information · Ctype — Character type checking · Filter — Data Filtering · Function Handling · Quickhash ...