objective-c,lambda,closures,objective-c-blocks , Is Java's Lambda equivalent to Objective-C Blocks? [closed]


Is Java's Lambda equivalent to Objective-C Blocks? [closed]

Question:

Tag: objective-c,lambda,closures,objective-c-blocks

I noticied that Java's Lambda expressions seem equivalent to Objective-C blocks.

Are Java's Lambda expressions exactly equivalent to Objective-C's Blocks? If not, what make's Objective-C blocks different?


Answer:

On a very high level, yes, they are: both the blocks and the lambdas are said to implement closures. Very informally, they serve the same purpose of "packaging" executable logic together with data on which the logic operates, for the purpose of passing it around or storing for deferred execution.

However, there are many important differences when you get into the implementation of blocks, and the language surrounding them.

For example, lambdas in Java could be thought of as shortcuts for creating anonymous inner classes that implement a single-method interface. An object of a class that implements the same interface can go wherever a lambda can go.

In contrast, blocks in Objective-C are a separate concept from protocols (which could be thought of as a counterpart of Java interfaces). If a method is declared with a parameter of a block type, you must supply a block to it; you cannot substitute a non-block object for a block.


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