Java - Passing and executing a function

Question

Is there a way of passing a function to another function and then executing it?

functionCaller(functionToBeCalled());

score 1 · Accepted Answer · answered Jan 20 '16 at 15:35

1

In java 8 you can use a method reference or lambda

functionCaller(this::functionToBeCalled);

or

functionCaller(() -> functionToBeCalled());

answered Jan 20 '16 at 15:35

Peter Lawrey

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Thank you, finally a simple way. I'll mark this as answer when I'll be able. – Device Jan 20 '16 at 15:37
1

Note that `this::functionToBeCalled` won't work if you're in a static context. – Tunaki Jan 20 '16 at 15:52
@Tunaki in that case you need to know the class e.g. `MyClass::functionToBeCalled` – Peter Lawrey Jan 20 '16 at 17:41

score 1 · Answer 2 · answered Jan 20 '16 at 15:56

I don't know if I understand very well your question, but effectively you can call a function in param of another function.

You can do this (I suppose your current language is Java):

// if write(...) and getValue() are static method of Writer class  
Writer.write(getValue());

// if write(...) and getValue() can just be used by instanciate an object
Writer writer = new Writer();
String val = writer.getValue();
writer.write(val);

There are basic Java programming lesson. Thanks

The pattern the OP is looking for is the ability to pass in a function to be called, but is not called first. — Peter Lawrey, Jan 20 '16 at 17:42

Java - Passing and executing a function

2 Answers2