Eclipse keeps giving me the following error:
Eclipse始终给我以下错误:
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
input cannot be resolved
The method If(boolean) is undefined for the type bai1DinhLuatCuLong
Syntax error, insert ";" to complete Statement
F cannot be resolved to a variable
I do not understand this. What do I need to fix? Why can't I use the If()
function?
我不明白这一点。我需要解决什么问题?为什么我不能使用If()函数?
I've tried looking through Google and Bing, and I've double checked my Java examples book, but I could not work this out.
我已经尝试过查看谷歌和Bing,我已经仔细检查了我的Java例子,但是我不能解决这个问题。
import java.util.Scanner;
public class bai1DinhLuatCuLong
{
public static void main(String[] args)
{
System.out.print("Giá trì cần tìm (F // q // r) : ");
char cantim = input.nextChar();
// HERE THIS IS WHERE I PUT THE IF STATEMENT !!!
If (cantim == 'F') {
Scanner input = new Scanner(System.in);
System.out.print("Độ lớn của điện tích thứ nhất : ");
double q1 = input.nextDouble();
System.out.print("Độ lớn của điện tích thứ hai : ");
double q2 = input.nextDouble();
System.out.print("Khoảng cách giữa 2 điện tích : ");
double r = input.nextDouble();
System.out.print("Hệ số k sẽ tự động được đặt là 9*10^9 như trong hệ SI");
double F = 9 * Math.pow(10,9) * Math.abs(q1) * Math.abs(q2) / Math.pow(r,2);
}
System.out.print("Độ lớn lực tương tác giữa 2 điện tích điểm : " + "\n Lưu ý E là *10");
}
}
3 个解决方案
#1
12
If
does not have a large cap I
in java: it should be if
.
如果在java中没有大写I,应该是If。
#2
6
if (cantim == 'F')
it should be small i
如果(cantim = 'F')应该是小i。
or
或
You need to write a method
你需要写一个方法。
public boolean If(boolean test)
{
//Your logic.
}
But, based on your code, it seems you are looking for "if"
statement than having new method.
但是,基于您的代码,您似乎正在寻找“if”语句,而不是使用新方法。
#3
0
Maybe You want to do something like this:
也许你想做这样的事情:
Scanner input = new Scanner(System.in);
String cantim = input.next();
if (cantim.equals("F")) {
System.out.println("If F");
} else {
System.out.println("Out of F");
}
#1
12
If
does not have a large cap I
in java: it should be if
.
如果在java中没有大写I,应该是If。
#2
6
if (cantim == 'F')
it should be small i
如果(cantim = 'F')应该是小i。
or
或
You need to write a method
你需要写一个方法。
public boolean If(boolean test)
{
//Your logic.
}
But, based on your code, it seems you are looking for "if"
statement than having new method.
但是,基于您的代码,您似乎正在寻找“if”语句,而不是使用新方法。
#3
0
Maybe You want to do something like this:
也许你想做这样的事情:
Scanner input = new Scanner(System.in);
String cantim = input.next();
if (cantim.equals("F")) {
System.out.println("If F");
} else {
System.out.println("Out of F");
}