最简单的java源代码大全

Hello World
java
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello World!");
}
}
基本数据类型
java
int number = 10;
double decimal = 10.5;
boolean flag = true;
char letter = 'a';
String text = "Hello Java";
变量
java
int age = 25;
String name = "John Doe";
常量
java
final int MAX_VALUE = 100;
运算符
| 运算符 | 描述 |
|---|---|
| + | 加法 |
| - | 减法 |
| | 乘法 |
| / | 除法 |
| % | 取余 |
| == | 等于 |
| != | 不等于 |
| > | 大于 |
| < | 小于 |
| >= | 大于等于 |
| <= | 小于等于 |
条件语句
java
if (age >= 18) {
System.out.println("You are an adult.");
} else {
System.out.println("You are not an adult.");
}
循环
for 循环
java
for (int i = 0; i < 10; i++) {
System.out.println(i);
}
while 循环
java
while (age < 18) {
System.out.println("You are not an adult.");
age++;
}
方法
java
public void printHello() {
System.out.println("Hello");
}
类
java
public class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
接口
java
public interface Animal {
void makeSound();
}
异常处理
java
try {
// Code that may throw an exception
} catch (Exception e) {
// Code to handle the exception
}