How do you check if a variable is empty in C++?

To check if a string is empty or not, we can use the built-in empty() function in C++. The empty() function returns 1 if string is empty or it returns 0 if string is not empty. Similarly, we can also use the length() function to check if a given string is empty or not.

IS NULL empty PHP?

is_null() The empty() function returns true if the value of a variable evaluates to false . This could mean the empty string, NULL , the integer 0 , or an array with no elements. On the other hand, is_null() will return true only if the variable has the value NULL .

How do you check if a string is empty in PHP?

We can use empty() function to check whether a string is empty or not. The function is used to check whether the string is empty or not. It will return true if the string is empty.

Is empty function in C++?

C++ empty() function is used to check whether the set container is empty or not. It returns true if the set container is empty (size is 0) otherwise, it returns false.

Is empty in PHP?

PHP empty() Function The empty() function checks whether a variable is empty or not. This function returns false if the variable exists and is not empty, otherwise it returns true. The following values evaluates to empty: 0.

What is empty () C++?

What is list::empty()? list::empty() is an inbuilt function in C++ STL which is declared in header file. list::empty() checks whether the given list container is empty(size is 0) or not, and returns true value if the list is empty and false if the list is not empty.

How do you create an empty function in C++?

C++ set empty()

  1. Syntax. bool empty() const; // until C++ 11.
  2. Parameter. None.
  3. Return value. It returns true if the set container is empty (size is 0) otherwise, it returns false.
  4. Complexity. Constant.
  5. Iterator validity. No changes.
  6. Data Races. The container is accessed.
  7. Exception Safety.
  8. Example 1.