I created a simple example of a case where you might want to use a lambda in C. In the end, though, you could always just use a proper function with a pointer. If you use another compiler, it might not - in fact, probably doesn’t - have these features. These two things, combined with some abuse of the preprocessor, will let you stuff your function code right where you need it and relieve you of having to name each and every little function you write just to pass to another subroutine. That is an expression that can do everything a function can. In addition, you can use statement expressions. You have to use gcc, because this trick uses two nonstandard language features. However, if you use gcc, there are some nonstandard C features you can use to get most of what you want out of lambda expressions.

It’s just hard to think up that many disposable function names. However, in C you have to define a function by name and pass a pointer - not a huge problem, but it can get messy if you have a lot of callback functions that you use only one time. The map call ensures that the anonymous function is called once for each item. The anonymous function here takes an argument x and calls the capitalize method on it. However, map and a lambda can do it more concisely: map(lambda x: x.capitalize(), ) A Python string has a capitalize method and you could write a loop to apply it to each element in the list. Suppose you have a list and you want to capitalize each word in the list. Sometimes you need a little snippet of code that you only need in one place - most commonly, as a callback function to pass another function - so why bother giving it a name? Depending on the language, there can be more to it that, especially if you get into closures and currying.įor example, in Python, the map function takes a function as an argument. Some people make a big deal out of these but the core idea is very simple.

The Java compiler infers that you want to create a HashSet collection that contains elements of type Person.A lot of programming languages these days feature lambda functions, or what I would be just as happy to call anonymous functions. You can use a constructor reference in place of the lambda expression as follows: Set rosterSet = transferElements(roster, HashSet::new) Lambda Expressions: public class Person ) Method references enable you to do this they are compact, easy-to-read lambda expressions for methods that already have a name. In those cases, it's often clearer to refer to the existing method by name. Sometimes, however, a lambda expression does nothing but call an existing method. Lambda expressions to create anonymous methods.

C member function to lambda