Java basics – introduction to functional programming

Introduction to functional programming

Thought

Object-oriented thinking: find an object, call the method of the object, and complete the task.

Functional programming idea: As long as you can get results, focus on results instead of process.

Lambda expression

new Thread(()->{
    //do something
}).start();

• No parameters
• No return value
• Code block: the specific execution steps of the program

Format

There are three parts

• Some parameters: leave them blank if there are no parameters, write parameters if there are parameters, multiple parameters are separated by commas
• An arrow: the meaning of passing, passing parameters to the method body
• A piece of code: rewrite the method body of the interface abstract method

(Parameter list)->(some rewrite method code);

Lambda omitted format

Lambda expressions can be deduced and omitted, and everything that can be deduced can be omitted

What can be omitted:

1. Parameter list: The data type of the parameter list in parentheses can be omitted.
2. Parameter list: there is only one parameter in brackets, type and () can be omitted
3. Some codes: If there is only one line of code in (), no matter whether there is a return value or not, {}, return, semicolon can be omitted (if it is omitted, it must be omitted together)