php empty variable

Gettype: Get the type of the variable.Intval: convert a variable to an integer.Doubleval: convert a variable to a Double Floating Point.Empty: determines whether the variable is configured.Is_array: determines whether the variable type is an array

Through learning the PHP language, you should know that it is a function-based HTML scripting language. The huge function library supports the implementation of PHP functions. Next we will introduce the usage of PHP functions isset () and empty.

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PHPisset () and empty () usage differences. The isset () function of PHP is generally used to check whether the variable is set in the format boolisset (mixedvar [, mixedvar [,...]). function: checks whether a return value is set for a variable. if

PHP's Isset () function is commonly used to detect whether a variable is setFormat: bool Isset (mixed var [, mixed Var [, ...]) Function: Detect whether the variable is set return value: Returns FALSE if the variable does not exist Returns FALSE

Can empty () replace isset () When php checks whether a variable is set ?. Let's first review empty and issetempty to check whether a variable is empty, 0, 0, NULL, FALSE, array (), var $ var; and objects without any attributes will be considered

empty-checks if a variable is empty Report a bug description BOOL Empty (mixed $var) If Var is a non-null or nonzero value, empty () returns FALSE. In other words, "", 0, "0", NULL, FALSE, Array (), Var $var; and objects that do not have any

PHP's Isset () function is commonly used to detect whether a variable is setFormat: bool Isset (mixed var [, mixed Var [, ...])Function: Detect whether the variable is setreturn value:Returns FALSE if the variable does not existReturns FALSE if the

By learning the language of PHP, you should know that it is a function-based HTML scripting language. The large library of functions supports the implementation of PHP language functions. Let's introduce the relevant usage of PHP function isset ()

PHP isset () and empty () the use of a different explanation, Issetempty PHP's Isset () function is commonly used to detect whether a variable is setFormat: bool Isset (mixed var [, mixed Var [, ...])Function: Detect whether the variable is