php empty string

PHP empty and empty string differences 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 properties will be considered empty and return TRUE

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

: This article mainly introduces the relationship between 0, null, empty, and false in PHP empty strings. For more information about PHP tutorials, see. // Determine the relationship between 0 and '', null, empty, and false $ A = 0; Echo

The PHP empty string describes the relationship between 0, null, empty, and false. If the method function is used incorrectly or is used less, if the logic sequence of several method functions is wrong, it may be a vulnerability and cannot be found

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'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

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

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