英文:
Why do I get this error in Java? Exception in thread "main" java.lang.Error: Unresolved compilation problems
问题
import java.util.Scanner;
public class linearequationproblemredo {
private double a;
private double b;
private double c;
private double d;
private double e;
private double f;
public void linearequationproblemredo(double a, double b, double c, double d, double e, double f) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
}
public double getA(){
return this.a;
}
public double getB(){
return this.b;
}
public double getC(){
return this.c;
}
public double getD(){
return this.d;
}
public double getE(){
return this.e;
}
public double getF(){
return this.f;
}
public boolean isSolvable(){
if(this.a * this.d - this.b * this.c == 0) return false;
return true;
}
public double getX(){
if(isSolvable()) return ((e * d) - (b * f))/((a * d) - (b * c));
return -1;
}
public double getY(){
if(isSolvable()) return ((a * f) - (e * c))/((a * d) - (b * c));
return -1;
}
public static void main(String []args){
Scanner input = new Scanner(System.in);
System.out.println("Enter a, b, c, d, e, f one at a time starting with a.");
double []in = new double[6];
for(int l = 0; l < 6; l++){
in[l] = input.nextDouble();
}
linearequationproblemredo test = new linearequationproblemredo(in[0], in[1], in[2], in[3], in[4], in[5]);
while(true){
System.out.println("Type in a-f to show what you have entered OR 'progress' to progress with the script.");
String t = input.next();
if(t.equals("progress")) break;
else if(t.equals("a")) System.out.println(test.getA());
else if(t.equals("b")) System.out.println(test.getB());
else if(t.equals("c")) System.out.println(test.getC());
else if(t.equals("d")) System.out.println(test.getD());
else if(t.equals("e")) System.out.println(test.getE());
else if(t.equals("f")) System.out.println(test.getF());
else System.out.println("Error, please enter a valid input.");
}
while(true){
System.out.println("To show the output of either x or y, enter 'x' or 'y' or type 'quit' to end the script.");
String output = input.next();
if(output.equals("quit")) break;
try{
if(!test.isSolvable()) throw new Exception();
if(output.equals("x")) System.out.println(test.getX());
else if(output.equals("y")) System.out.println(test.getY());
else System.out.println("Error, please enter a valid input.");
}catch (Exception e){
System.out.println("The equation has no solution.");
break;
}
}
}
}
英文:
I constantly get the following error when running this code:
"Exception in thread "main" java.lang.Error: Unresolved compilation problems: linearequationproblem cannot be resolved to a type linearequationproblem cannot be resolved to a type at linearequationproblemredo.main(linearequationproblemredo.java:86)"
import java.util.Scanner;
public class lineequation {
private double a;
private double b;
private double c;
private double d;
private double e;
private double f;
public void lineequation(double a, double b, double c, double d, double e, double f) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
}
public double getA(){
return this.a;
}
public double getB(){
return this.b;
}
public double getC(){
return this.c;
}
public double getD(){
return this.d;
}
public double getE(){
return this.e;
}
public double getF(){
return this.f;
}
public boolean isSolvable(){
if(this.a * this.d - this.b * this.c == 0) return false;
return true;
}
public double getX(){
if(isSolvable()) return ((e * d) - (b * f))/((a * d) - (b * c));
return -1;
}
public double getY(){
if(isSolvable()) return ((a * f) - (e * c))/((a * d) - (b * c));
return -1;
}
public static void main(String []args){
Scanner input = new Scanner(System.in);
System.out.println("Enter a, b, c, d, e, f one at a time starting with a. ");
double []in = new double[6];
for(int l = 0; l < 6; l++){
in[l] = input.nextDouble();
}
lineequation test = new lineequation(in[0], in[1], in[2], in[3], in[4], in[5]);
while(true){
System.out.println("Type in a-f to show what you have entered OR 'progress' to progress with the script.");
String t = input.next();
if(t.equals("progress")) break;
else if(t.equals("a")) System.out.println(test.getA());
else if(t.equals("b")) System.out.println(test.getB());
else if(t.equals("c")) System.out.println(test.getC());
else if(t.equals("d")) System.out.println(test.getD());
else if(t.equals("e")) System.out.println(test.getE());
else if(t.equals("f")) System.out.println(test.getF());
else System.out.println("Error, please enter a valid input. ");
}
while(true){
System.out.println("To show the output of either x or y, enter 'x' or 'y' or type 'quit' to end the script.");
String output = input.next();
if(output.equals("quit")) break;
try{
if(!test.isSolvable()) throw new Exception();
if(output.equals("x")) System.out.println(test.getX());
else if(output.equals("y")) System.out.println(test.getY());
else System.out.println("Error, please enter a valid input. ");
}catch (Exception e){
System.out.println("The equation has no solution.");
break;
}
}
}
}
答案1
得分: 2
import java.util.Scanner;
public class lineequation {
private double a;
private double b;
private double c;
private double d;
private double e;
private double f;
public lineequation(double a, double b, double c, double d, double e, double f) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
}
public double getA(){
return this.a;
}
public double getB(){
return this.b;
}
public double getC(){
return this.c;
}
public double getD(){
return this.d;
}
public double getE(){
return this.e;
}
public double getF(){
return this.f;
}
public boolean isSolvable(){
if(this.a * this.d - this.b * this.c == 0) return false;
return true;
}
public double getX(){
if(isSolvable()) return ((e * d) - (b * f))/((a * d) - (b * c));
return -1;
}
public double getY(){
if(isSolvable()) return ((a * f) - (e * c))/((a * d) - (b * c));
return -1;
}
public static void main(String []args){
Scanner input = new Scanner(System.in);
System.out.println("Enter a, b, c, d, e, f one at a time starting with a.");
double []in = new double[6];
for(int l = 0; l < 6; l++){
in[l] = input.nextDouble();
}
lineequation test = new lineequation(in[0], in[1], in[2], in[3], in[4], in[5]);
while(true){
System.out.println("Type in a-f to show what you have entered OR 'progress' to progress with the script.");
String t = input.next();
if(t.equals("progress")) break;
else if(t.equals("a")) System.out.println(test.getA());
else if(t.equals("b")) System.out.println(test.getB());
else if(t.equals("c")) System.out.println(test.getC());
else if(t.equals("d")) System.out.println(test.getD());
else if(t.equals("e")) System.out.println(test.getE());
else if(t.equals("f")) System.out.println(test.getF());
else System.out.println("Error, please enter a valid input.");
}
while(true){
System.out.println("To show the output of either x or y, enter 'x' or 'y' or type 'quit' to end the script.");
String output = input.next();
if(output.equals("quit")) break;
try{
if(!test.isSolvable()) throw new Exception();
if(output.equals("x")) System.out.println(test.getX());
else if(output.equals("y")) System.out.println(test.getY());
else System.out.println("Error, please enter a valid input.");
}catch (Exception e){
System.out.println("The equation has no solution.");
break;
}
}
}
}
英文:
A class can be instantiated via the constructor . so you need to make linearequationproblem as a constructor like below.
import java.util.Scanner;
public class lineequation {
private double a;
private double b;
private double c;
private double d;
private double e;
private double f;
public lineequation(double a, double b, double c, double d, double e, double f) {
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
}
public double getA(){
return this.a;
}
public double getB(){
return this.b;
}
public double getC(){
return this.c;
}
public double getD(){
return this.d;
}
public double getE(){
return this.e;
}
public double getF(){
return this.f;
}
public boolean isSolvable(){
if(this.a * this.d - this.b * this.c == 0) return false;
return true;
}
public double getX(){
if(isSolvable()) return ((e * d) - (b * f))/((a * d) - (b * c));
return -1;
}
public double getY(){
if(isSolvable()) return ((a * f) - (e * c))/((a * d) - (b * c));
return -1;
}
public static void main(String []args){
Scanner input = new Scanner(System.in);
System.out.println("Enter a, b, c, d, e, f one at a time starting with a. ");
double []in = new double[6];
for(int l = 0; l < 6; l++){
in[l] = input.nextDouble();
}
lineequation test = new lineequation(in[0], in[1], in[2], in[3], in[4], in[5]);
while(true){
System.out.println("Type in a-f to show what you have entered OR 'progress' to progress with the script.");
String t = input.next();
if(t.equals("progress")) break;
else if(t.equals("a")) System.out.println(test.getA());
else if(t.equals("b")) System.out.println(test.getB());
else if(t.equals("c")) System.out.println(test.getC());
else if(t.equals("d")) System.out.println(test.getD());
else if(t.equals("e")) System.out.println(test.getE());
else if(t.equals("f")) System.out.println(test.getF());
else System.out.println("Error, please enter a valid input. ");
}
while(true){
System.out.println("To show the output of either x or y, enter 'x' or 'y' or type 'quit' to end the script.");
String output = input.next();
if(output.equals("quit")) break;
try{
if(!test.isSolvable()) throw new Exception();
if(output.equals("x")) System.out.println(test.getX());
else if(output.equals("y")) System.out.println(test.getY());
else System.out.println("Error, please enter a valid input. ");
}catch (Exception e){
System.out.println("The equation has no solution.");
break;
}
}
}
}
答案2
得分: 0
我认为你在Java方面完全是个新手。
一个很好的起点是Java教程，然后继续学习Oracle Java教程
这段代码无法编译，存在以下问题：
-
类名为lineequation，构造函数名为linearequationproblem，这是不被允许的。在Java中，类名和构造函数名应该相同，因为构造函数是用于创建类的实例并初始化成员变量的特殊方法。
-
第56行：
java linearequationproblem test = new linearequationproblem(in[0], in[1], in[2], in[3], in[4], in[5]);
你尝试创建一个linearequationproblem的实例，但这种类型（类）不存在。 -
private double f;` 那个反引号是不合法的，会导致编译失败，因为这不是正确的语法。
你可以参考上面的文档以获取关于Java的更多细节。享受学习吧！
英文:
I think you are completely new in Java.
A good starting point is Java Tutorials and then move on to Oracle Java Tutorials
This code wont compile and these are the problems:
-
The class name is lineequation and the constructor name is linearequationproblem, which is not allowed. In Java class name and constructor name should be same, since constructor is a special method for creating the instance of the class and initializing the member variables.
-
Line 56:
java
linearequationproblem test = new linearequationproblem(in[0], in[1], in[2], in[3], in[4], in[5]);
You are trying to create and instance of linearequationproblem but this type (Class) does not exists. -
private double f;` That backtick is not legit and will fail to compile, since this is not a correct syntax.
You can refer the docs above for more details about Java. Enjoy Learning !
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
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