java方法methods

java中还是称之为“方法”好了。

In general, method declarations has six components :

包括这六部分：

• Modifier-（标识符）: Defines access type of the method i.e. from where it can be accessed in your application. In Java, there 4 type of the access specifiers.
  • public: accessible in all class in your application.
  • protected: accessible within the class in which it is defined and in its subclass(es)
  • private: accessible only within the class in which it is defined.
  • default (declared/defined without using any modifier) : accessible
    within same class and package within which its class is defined.
• The return type（返回值） : The data type of the value returned by the method or void if does not return a value.
• Method Name （方法名）: the rules for field names apply to method names as well, but the convention is a little different.
• Parameter list （参数列表）: Comma separated list of the input parameters are defined, preceded with their data type, within the
  enclosed parenthesis. If there are no parameters, you must use empty
  parentheses ().
• Exception list （异常列表）: The exceptions you expect by the method can throw, you can specify these exception(s).可以列出方法可能的异常会被引发，在此列表中可以指定这些异常。
• Method body : it is enclosed between braces. The code you need to be executed to perform your intended operations.

How to name a Method?

A method name is typically a single word that should be a verbin lowercase or multi-word, that begins with a verb in lowercase followed by adjective, noun….. After the first word, first letter of each word should be capitalized. For example, findSum, computeMax, setX and get.

方法的命名通常为动词（小写）后可跟一个名词（后面的单词首字母大写）。computeMax。

//自己写的
import java.util.Scanner;
class Addition{
    int sum;
    public int addTwoInt(int a,int b) {
        sum = a + b;
        return sum;
    }
}

public class Main {
    public  static void main(String args[]){
        Addition add = new Addition();
        int s = add.addTwoInt(1,2);
        System.out.print(s);
    }

}

// 标准版本
//Program to illustrate methodsin java 
import java.io.*; 

class Addition { 

    int sum = 0; 

    public int addTwoInt(int a, int b){ 

        // adding two integer value. 
        sum = a + b; 

        //returning summation of two values. 
        return sum; 
    } 

} 

class GFG { 
    public static void main (String[] args) { 

        // creating an instance of Addition class 
        Addition add = new Addition(); 

        // calling addTwoInt() method to add two integer using instance created 
        // in above step. 
        int s = add.addTwoInt(1,2); 
        System.out.println("Sum of two integer values :"+ s); 

    } 
}