how java compiler solved lambda return type while Predicate's method can only return boolean?
Note: this question look like some others but different
Things i can't understand is that we know java doesn't support dynamic type even use Lambda, and it's compiled to Predictor during compile time.
Things i can't understand is that Predicator's default method only can return boolean, while Lambda expression can return anything. HOW is this archived?
java lambda
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
add a comment |
Note: this question look like some others but different
Things i can't understand is that we know java doesn't support dynamic type even use Lambda, and it's compiled to Predictor during compile time.
Things i can't understand is that Predicator's default method only can return boolean, while Lambda expression can return anything. HOW is this archived?
java lambda
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
What is aPredicator? And Lambdas are compiled to implement a functional interface.
– Henry
Nov 20 at 10:03
1
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
He probably meansjava.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.
– Dvorog
Nov 20 at 10:24
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31
add a comment |
Note: this question look like some others but different
Things i can't understand is that we know java doesn't support dynamic type even use Lambda, and it's compiled to Predictor during compile time.
Things i can't understand is that Predicator's default method only can return boolean, while Lambda expression can return anything. HOW is this archived?
java lambda
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
Note: this question look like some others but different
Things i can't understand is that we know java doesn't support dynamic type even use Lambda, and it's compiled to Predictor during compile time.
Things i can't understand is that Predicator's default method only can return boolean, while Lambda expression can return anything. HOW is this archived?
java lambda
java lambda
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
edited Nov 20 at 12:59
Federico Peralta Schaffner
21.8k43369
21.8k43369
asked Nov 20 at 10:00
Ben Xu
6552720
asked Nov 20 at 10:00
Ben Xu
6552720
asked Nov 20 at 10:00
Ben Xu
6552720
6552720
What is aPredicator? And Lambdas are compiled to implement a functional interface.
– Henry
Nov 20 at 10:03
1
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
He probably meansjava.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.
– Dvorog
Nov 20 at 10:24
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31
add a comment |
What is aPredicator? And Lambdas are compiled to implement a functional interface.
– Henry
Nov 20 at 10:03
1
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
He probably meansjava.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.
– Dvorog
Nov 20 at 10:24
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31
What is a
Predicator? And Lambdas are compiled to implement a functional interface.– Henry
Nov 20 at 10:03
What is a
Predicator? And Lambdas are compiled to implement a functional interface.– Henry
Nov 20 at 10:03
1
1
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
He probably means
java.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.– Dvorog
Nov 20 at 10:24
He probably means
java.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.– Dvorog
Nov 20 at 10:24
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31
add a comment |
1 Answer
1
active
oldest
votes
while Lambda expression can return anything. This is wrong
A lambda expression is written to a corresponding abstract method in a function interface
Considering Predicate as an example, lambda expression will be written to corresponding abstract method which is boolean test(T t)
From java docs here with an clear example
A functional interface is any interface that contains only one abstract method. (A functional interface may contain one or more default methods or static methods.) Because a functional interface contains only one abstract method, you can omit the name of that method when you implement it. To do this, instead of using an anonymous class expression, you use a lambda expression, which is highlighted in the following method invocation:
Refer : Approach 5: Specify Search Criteria Code with a Lambda Expression
Refer : Approach 6: Use Standard Functional Interfaces with Lambda Expressions
answered Nov 20 at 10:05
Deadpool
3,5692324
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
while Lambda expression can return anything. This is wrong
A lambda expression is written to a corresponding abstract method in a function interface
Considering Predicate as an example, lambda expression will be written to corresponding abstract method which is boolean test(T t)
From java docs here with an clear example
A functional interface is any interface that contains only one abstract method. (A functional interface may contain one or more default methods or static methods.) Because a functional interface contains only one abstract method, you can omit the name of that method when you implement it. To do this, instead of using an anonymous class expression, you use a lambda expression, which is highlighted in the following method invocation:
Refer : Approach 5: Specify Search Criteria Code with a Lambda Expression
Refer : Approach 6: Use Standard Functional Interfaces with Lambda Expressions
answered Nov 20 at 10:05
Deadpool
3,5692324
add a comment |
while Lambda expression can return anything. This is wrong
A lambda expression is written to a corresponding abstract method in a function interface
Considering Predicate as an example, lambda expression will be written to corresponding abstract method which is boolean test(T t)
From java docs here with an clear example
A functional interface is any interface that contains only one abstract method. (A functional interface may contain one or more default methods or static methods.) Because a functional interface contains only one abstract method, you can omit the name of that method when you implement it. To do this, instead of using an anonymous class expression, you use a lambda expression, which is highlighted in the following method invocation:
Refer : Approach 5: Specify Search Criteria Code with a Lambda Expression
Refer : Approach 6: Use Standard Functional Interfaces with Lambda Expressions
answered Nov 20 at 10:05
Deadpool
3,5692324
add a comment |
while Lambda expression can return anything. This is wrong
A lambda expression is written to a corresponding abstract method in a function interface
Considering Predicate as an example, lambda expression will be written to corresponding abstract method which is boolean test(T t)
From java docs here with an clear example
A functional interface is any interface that contains only one abstract method. (A functional interface may contain one or more default methods or static methods.) Because a functional interface contains only one abstract method, you can omit the name of that method when you implement it. To do this, instead of using an anonymous class expression, you use a lambda expression, which is highlighted in the following method invocation:
Refer : Approach 5: Specify Search Criteria Code with a Lambda Expression
Refer : Approach 6: Use Standard Functional Interfaces with Lambda Expressions
answered Nov 20 at 10:05
Deadpool
3,5692324
while Lambda expression can return anything. This is wrong
A lambda expression is written to a corresponding abstract method in a function interface
Considering Predicate as an example, lambda expression will be written to corresponding abstract method which is boolean test(T t)
From java docs here with an clear example
A functional interface is any interface that contains only one abstract method. (A functional interface may contain one or more default methods or static methods.) Because a functional interface contains only one abstract method, you can omit the name of that method when you implement it. To do this, instead of using an anonymous class expression, you use a lambda expression, which is highlighted in the following method invocation:
Refer : Approach 5: Specify Search Criteria Code with a Lambda Expression
Refer : Approach 6: Use Standard Functional Interfaces with Lambda Expressions
answered Nov 20 at 10:05
Deadpool
3,5692324
edited Nov 20 at 10:11
answered Nov 20 at 10:05
Deadpool
3,5692324
answered Nov 20 at 10:05
Deadpool
3,5692324
answered Nov 20 at 10:05
Deadpool
3,5692324
3,5692324
add a comment |
add a comment |
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What is a
Predicator? And Lambdas are compiled to implement a functional interface.– Henry
Nov 20 at 10:03
1
"this question look like some others but different". Whenever you say anything like this in a question, you should explain what you have already found and how its different from what you're asking.
– Michael
Nov 20 at 10:04
He probably means
java.util.function.Predicate. Anyway, I believe that this question is a bit too broad for stackoverflow, because the answer would be an explanation of how lambdas work in java.– Dvorog
Nov 20 at 10:24
i mean "java.util.function.Predicate"
– Ben Xu
Nov 21 at 6:31