What are the functions of php empty function

php editor Xiaoxin introduces to you the empty() function in php. The empty() function is used to check whether a variable is empty. The function will return a Boolean value. If the variable is empty, it returns true, otherwise it returns false. . This function can be used to check whether a variable exists, whether it is an empty string, whether it is 0, whether it is null, etc. When writing PHP code, the empty() function is a commonly used tool that can help us perform effective variable checking and processing.

1. Check whether the variable is empty: The empty function can detect whether a variable is empty. If the variable value is 0, empty string, empty array, null, false, or undefined, then return true, otherwise return false.

2. Check whether the array is empty: When the incoming parameter is an array, the empty function will determine whether the array is empty, that is, whether the array contains elements. Returns true if the array is empty, false otherwise.

3. Check whether the string is empty: When the incoming parameter is a string, the empty function will determine whether the string is an empty string. Returns true if the string is empty, false otherwise.

4. Check whether the object is empty: When the incoming parameter is an object, the empty function will call the object's __isset() magic method to determine whether the object is empty. If the __isset() method returns false, it means that the object is empty, and the empty function returns true, otherwise it returns false.

It should be noted that the empty function will return true when judging 0, which is different from the judgment methods of some other programming languages, so you need to pay attention to its use.

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