How to use php empty function

php Editor Xigua today will introduce to you how to correctly use the empty function in PHP. The empty function is used to determine whether a variable is empty. It can be used to detect whether the variable exists or is a non-empty value. In actual development, the empty function is a very convenient judgment tool that can help us better handle the status of variables. Next, we will introduce the use of empty function in detail, hoping to be helpful to everyone.

if (empty($variable)) {
// 变量为空
} else {
// 变量不为空
}

In this example, $variable is the variable to be checked. If $variable is empty, that is, does not exist or has a value of false, 0, "", null, array(), the code in the if statement block will be executed. Otherwise, the code in the else statement block will be executed.

You can also directly use the empty function to determine whether the value of an expression is empty, for example:

if (empty($foo || $bar)) {
// 表达式的值为空
} else {
// 表达式的值不为空
}

In this example, $foo and $bar are two variables, and the empty function will determine whether the result of the logical OR operation of $foo and $bar is empty. If the result is empty, the code in the if statement block is executed.

It should be noted that the empty function can only be used for variables and expressions, and cannot be used for the return value of a function. If you want to determine whether the return value of a function is empty, you can first assign the return value of the function to a variable, and then use the empty function to determine the value of the variable.

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