[Excellent Tutorial] Java Method (1)

Recently, some friends have responded, hoping that Xiaozhuo can help everyone find some knowledge about Java methods. Today Xiaozhuo recommends an article about Java methods to everyone, which is suitable for newcomers to learn.

We often use System.out.println(), so what is it?

println() is a method (Method), and System is the system class (Class), and out is the standard output object (Object). The usage of this sentence is to call the method println() in the standard output object out in the system class System.

So what is the method?

Java methods are a collection of statements that together perform a function.

1) A method is an ordered combination of steps to solve a type of problem

2) A method is contained in a class or object

3) A method is created in a program, Referenced elsewhere

Definition of method

Generally, defining a method contains the following syntax:

Modifier return value type method name (Parameter type parameter name) {

...

Method body

...

return return value;}

The method contains a method header and a method body. The following are all parts of a method:

1) Modifiers: Modifiers, which are optional, tell the compiler how to call the method. Defines the access type for this method.

2) Return value type: Methods may return values. returnValueType is the data type of the method return value. Some methods perform the required operation but do not return a value. In this case, returnValueType is the keyword void.

3) Method name: It is the actual name of the method. The method name and parameter list together form the method signature.

4) Parameter type: The parameter is like a placeholder. When the method is called, values ​​are passed to the parameters. This value is called an actual parameter or variable. The parameter list refers to the parameter type, order and number of parameters of the method. Parameters are optional and methods can contain no parameters.

5) Method body: The method body contains specific statements that define the function of the method.

public static int age(int birthday){...}

static float interest(float principal, int year){...}

/** 返回两个整型变量数据的较大值 */public static int max(int num1, int num2) {
int result;
if (num1 > num2)
result = num1;
else
result = num2;
return result; }

System.out.println("Welcome to Java!");

public class TestMax {
 /** 主方法 */
public static void main(String[] args) {
int i = 5;
int j = 2;
int k = max(i, j);
System.out.println("The maximum between " + i +
" and " + j + " is " + k);
}
/** 返回两个整数变量较大的值 */
public static int max(int num1, int num2) {
int result;
if (num1 > num2) result = num1;
else
result = num2;
return result; }}

The maximum between 5 and 2 is 5