Java basic learning content 9 (lambda expression)

Overview

Lambda expression: One of the notations for functions (= anonymous functions) that are defined without naming. Describe arguments and processing.

notation

`Lambda expression(Basic grammar)`


 Function<int> func1 = (int num) -> { return num + 1};
 Function<int> func2 = num -> { return num + 2};
 Function<int> func3 = num -> num + 3;

The argument type can be omitted because it is determined when the interface is declared.
If there is only one argument, the argument () can be omitted.
If the process is one line, {} and return can be omitted.

use

If you use a method that takes a lambda expression as an argument, you can pass a part of the process as an argument. ・ Stream related -ReplaceAll of ArrayList ・ Self-made method And so on… As an example, see (the above)

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