u200b illegal character / java

Question

Could anyone please help in this

public class siham{
​​public static void main(String[] args){
​​int x=15;
​​sentence(x, 4);
​​int y= x-5;
​​sentence (y,x);
​​System.out.println(x+ "&" + y);
​public static void sentence(int num1, int num2){
num1=num1+num2;
}
​​ }
​​}

Answer 1

Below is a cleansing of the code:

public class siham{
public static void main(String[] args){
int x=15;
sentence(x,4);
int y = x-5;
sentence(y,x);
System.out.println(x+"&"+y);
}

public static void sentence(int num1, int num2){
num1 = num1+num2;
}
}

Answer 2

Ipang and Siham Apologies!

I've heard of u+200b JS backdooring, but I'm not seeing any resources to support my claim.

Answer 3

u+200b is the unicode for a character that is 'unseen' and is well known as a troll character, hence illegal in most IDE's.

Your solution is to delete all of your code and rewrite it.

P.S. Most IDE's now a days (VS Code) implement a feature that exposes the u+200b character.

Answer 4

Charles Jones,
It's interesting to know that invalid characters can be used to create a backdoor. How does it work when the compiler refuses to process those characters?

Can you please elaborate further on that subject?

Answer 5

Thank you now its work