大牛们,有空,帮我解答下,刚自学java不久,很多东西不懂。
题目为:定义公有变量,私有变量,公有方法,私有方法,并调用,查看程序运行结果。请问哪里出错了。
public class hi{
int i = 6;
public static void f(){
System.out.println("这个是共有方法!");
}
public static void main(String agrs[]){
int i = 10;
hi a = new hi();
int sum(int i){
int sum;
for (int j=0; j<i; j++){
sum = sum + j;
}
return sum;
}
a.f();
System.out.println("这个是共有变量i = "+a.i+"这个事私有变量i = "+i);
System.out.println("这个是私有方法:"+sum(i));
}
}
题目为:定义公有变量,私有变量,公有方法,私有方法,并调用,查看程序运行结果。请问哪里出错了。
public class hi{
int i = 6;
public static void f(){
System.out.println("这个是共有方法!");
}
public static void main(String agrs[]){
int i = 10;
hi a = new hi();
int sum(int i){
int sum;
for (int j=0; j<i; j++){
sum = sum + j;
}
return sum;
}
a.f();
System.out.println("这个是共有变量i = "+a.i+"这个事私有变量i = "+i);
System.out.println("这个是私有方法:"+sum(i));
}
}
public class hi { int i = 6; public static void f() {
System.out.println("这个是共有方法!");
} public static void main(String agrs[]) {
int i = 10; hi a = new hi(); a.f();
System.out.println("这个是共有变量i = " + a.i + "这个事私有变量i = " + i);
System.out.println("这个是私有方法:" + sum(i));
} private static int sum(int i) {
int sum = 0;
for (int j = 0; j < i; j++) {
sum = sum + j;
}
return sum;
}
}
public class hi{
int i = 6;public static void f(){
System.out.println("这个是共有方法!");
}
int sum(int i){
int sum=0;
for (int j=0; j<i; j++){
sum = sum + j;
}
return sum;
}public static void main(String agrs[]){
int i = 10;hi a = new hi();
a.f();
System.out.println("这个是共有变量i = "+a.i+"这个事私有变量i = "+i);
System.out.println("这个是私有方法:"+a.sum(i));
}
}错误不少,我给你改过了
public class Test {
public int a; //public value
private int b;//private value
public int getA() {
return a;
}
public void setA(int a) {
this.a = a;
}
public int getB() {
return b;
}
public void setB(int b) {
this.b = b;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Test test=new Test();
test.setA(10);
test.setB(100);
System.out.println("public:"+test.getA());
System.out.println("private:"+test.getB());
System.out.println("public method :test.AA(test.getA(), test.getB())="+test.AA(test.getA(), test.getB()));
System.out.println("private method:test.Sum(test.getA())="+test.Sum(test.getA()));
}
private int Sum(int a){ //private method
int total=0;
for(int i=0;i<a;i++){
total+=i;
}
return total;
}
public int AA(int a, int b){ //public method
int A=Sum(a)+Sum(b);
return A;
}
}
private static int sum(int i) {
^
hi.java:18: 错误: 非法的表达式开始
private static int sum(int i) {
^
hi.java:18: 错误: 需要';'
private static int sum(int i) {
^
hi.java:18: 错误: 需要 '.class'
private static int sum(int i) {
^
hi.java:18: 错误: 需要';'
private static int sum(int i) {
^
5 个错误
private static int sum(int i) {
^
hi.java:18: 错误: 非法的表达式开始
private static int sum(int i) {
^
hi.java:18: 错误: 需要';'
private static int sum(int i) {
^
hi.java:18: 错误: 需要 '.class'
private static int sum(int i) {
^
hi.java:18: 错误: 需要';'
private static int sum(int i) {
^
5 个错误
public class hi{
int i = 6;public static void f(){
System.out.println("这个是共有方法!");
}public static void main(String agrs[]){
int i = 10;hi a = new hi();
//大括号加在这里 --------}
int sum(int i){
int sum;//声明局部变量时,一定要赋值
for (int j=0; j<i; j++){
sum = sum + j;
}
return sum;
}a.f();//加到man方法里面
System.out.println("这个是共有变量i = "+a.i+"这个事私有变量i = "+i);//加到main方法里面
System.out.println("这个是私有方法:"+sum(i)//静态的方法里面怎能调用非静态的方法);//加到main方法里面
}//括号个去掉、注意作用域
}
整体修改如下:
public class hi{
int i = 6;
public static void f(){
System.out.println("这个是共有方法!");
}public static void main(String agrs[]){
int i = 10;hi a = new hi();a.f();
System.out.println("这个是共有变量i = "+a.i+"这个事私有变量i = "+i);
System.out.println("这个是私有方法:"+sum(i));
}
static int sum(int i){
int sum=0;
for (int j=0; j<i; j++){
sum = sum + j;
}
return sum;
}
}
如果不能,那是为什么呢?