public class Demo01 {
//main方法
public static void main(String[] args) {
int sum = add(1,2);
System.out.println(sum);
test();
}
//加法
public static int add(int a, int b){
return a+b;
}
public static void test() {
for (int i = 1; i <= 5; i++) {
for (int j = 5; j >= i; j--) {
System.out.print(" ");
}
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
for (int j = 1; j < i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}
Resultado de salida:
3
*
***
*****
*******
*********
Descompilar
Código fuente
public class Demo02 {
public static int getSum (int x, int y){
if (x <= 0 || y <= 0 ){
return -1;
}return x+y;
}/*这样的程序对传入的参数值进行了检查控制;
许多程序错误都是由非法参数引起的*/
public static void main(String[] args) {
int sum = getSum(4, 5);
System.out.println("Add 1 = "+sum);
System.out.println("Add 2 = "+getSum(2, 4));
getSum(6, 10);
}
}
El resultado después de la descompilación.
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//
package com.cuckoo.method;
public class Demo02 {
public Demo02() {
}
public static int getSum(int x, int y) {
return x > 0 && y > 0 ? x + y : -1;
}
public static void main(String[] args) {
int sum = getSum(4, 5);
System.out.println("Add 1 = " + sum);
System.out.println("Add 2 = " + getSum(2, 4));
getSum(6, 10);
}
}