What is a lambda function ?

1.  any function that makes use of scientific or mathematical constants, often represented by Greek letters in academic writing
2.  a function that get executed when decorators are used
3.  any function whose definition is contained within five lines of code or fewer
4.  a small, anonymous function that can take any number of arguments but has only expression to evaluate

Correct Answer:

•  a small, anonymous function that can take any number of arguments but has only expression to evaluate

Explanation: the lambda notation is basically an anonymous function that can take any number of arguments with only single expression (i.e, cannot be overloaded). It has been introducted in other programming languages, such as C++ and Java. The lambda notation allows programmers to "bypass" function declaration.