empty Determine whether a variable is empty &reftitle.description; boolempty mixedvar Determine whether a variable is considered to be empty. &reftitle.parameters; var Variable to be checked empty only checks variables as anything else will result in a parse error. In other words, the following will not work: empty(trim($name)). empty is the opposite of (boolean) var, except that no warning is generated when the variable is not set. &reftitle.returnvalues; Returns &false; if var has a non-empty and non-zero value. The following things are considered to be empty: "" (an empty string) 0 (0 as an integer) 0.0 (0 as a float) "0" (0 as a string) &null; &false; array() (an empty array) var $var; (a variable declared, but without a value in a class) &reftitle.changelog; &Version; &Description; 5.4.0 Checking non-numeric offsets of strings returns &true;. 5.0.0 Objects with no properties are no longer considered empty. &reftitle.examples; ]]> PHP 5.4 changes how empty behaves when passed string offsets. ]]> &example.outputs.53; &example.outputs.54; &reftitle.notes; ¬e.language-construct; When using empty on inaccessible object properties, the __isset() overloading method will be called, if declared. &reftitle.seealso; isset __isset() unset array_key_exists count strlen The type comparison tables