PHP中的"isset()"和“！empty()"有什么区别? [英] What's the difference between 'isset()' and '!empty()' in PHP?

问题描述

我不明白isset()和!empty()之间的区别.

I don't understand the difference between isset() and !empty().

因为已经设置了变量，这与不为空一样吗?

Because if a variable has been set, isn't it the same as not being empty?

推荐答案

ISSET 检查变量是否已设置.换句话说，它将检查变量是否为除NULL以外的任何值或未分配值.如果变量存在并且具有非NULL的值，则ISSET返回TRUE.这意味着设置了分配了"，0，"0"或FALSE的变量，因此对于ISSET是TRUE.

ISSET checks the variable to see if it has been set. In other words, it checks to see if the variable is any value except NULL or not assigned a value. ISSET returns TRUE if the variable exists and has a value other than NULL. That means variables assigned a "", 0, "0", or FALSE are set, and therefore are TRUE for ISSET.

空检查变量是否为空.空解释为:"(空字符串)，0(整数)，0.0(浮点数)，"0"(字符串)，NULL，FALSE，array()(空数组)和"$ var;" (已声明的变量，但在类中没有值.

EMPTY checks to see if a variable is empty. Empty is interpreted as: "" (an empty string), 0 (integer), 0.0 (float)`, "0" (string), NULL, FALSE, array() (an empty array), and "$var;" (a variable declared, but without a value in a class.

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