Lambda functions: Closures

- [Instructor] Let's do another lambda example.…This time we'll create a special function,…which we'll call Incrementer.…So we'll come up here, above the main.…We'll do auto space incrementer.…And we will set this equal to lambda.…And this time the lambda's not going to take…any parameters.…And then on the inside we'll say auto increment equal zero.…Then what this function returns is another lambda.…

And then we want to capture increment,…and once again we take no values,…and now we need to use a special keyword…which is called mutable.…Any time you want to modify a value…that's in the closure, you have to say mutable…in order to be able to change it.…And what we're going to do is we're going to say return…increment plus plus.…And then a semicolon.…And we need semicolons here, and here.…

So we have our little function called incrementer,…it is going to start off at zero,…and every time you call it, it's going to increase…its value by one.…And so let's comment this code back in.…Here we call increment the first time,…