Iambda expression compilation error

Question

I am using search of ConcurrentHashMap like this:

map.search(1, (k, v) -> {  
  return v.size() > 10 ? k : null;
});

But when I remove braces it gives me compilation error:

map.search(1, (k, v) -> 
  return v.size() > 10 ? return k : null;
);

I want to remove braces since it is single statement in lambda expression.

Update : corrected typo

Then also remove `return`, cf. https://stackoverflow.com/questions/11145696/when-are-braces-optional-in-java-8-lambda-syntax. — jensgram, Aug 08 '17 at 06:23

Brijesh Shah · Answer 1 · 2017-08-08T06:32:44.373

1

As there are 2 return statements, you can either have the braces as you posted above:

map.search(1, (k, v) -> {  
return v.size() > 10 ? return k : null;
});

Or you need to remove the other return:

map.search(1, (k, v) -> {  
return v.size() > 10 ? k : null;
});

For further knowledge, you can visit the following link:

https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html#syntax

edited Aug 08 '17 at 06:32

answered Aug 08 '17 at 06:26

Brijesh Shah

score 1 · Accepted Answer · answered Aug 08 '17 at 06:27

1

A return statement is not an expression , its a statement. In lambda expression you must enclose statement in {} braces. For further details you can study here : https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html#syntax

answered Aug 08 '17 at 06:27

sourabh1024

2 Answers2