How to use a variable from one java file on another?

Question

Java

"1.java" has a variable "x"(string). how to use this "x" on "2.java"?

Answer 1

Your question is a bit odd, but it's understandable. Let's not 1/2.java (because class names must match file names, and in java classes cannot be named numbers), but at least First.java and Second.java
In Second.java, write first
import First;
and further on the code in Second.java write
x=First.var1
This is if var1 is static. Otherwise, you would first have to instantiate the First object and then call access to var1 on behalf of the instance.
Although personally it seems to me that you have just started learning java. See section Scopes, Modularity, your question is from there.

Answer 2

You can pass it to the constructor when creating an instance of class 2

public class Main {
    
    static String x = "Тут ваша строка";
    
    public static void main(String[] args) {
        Main2 Main2 = new Main2(x);
    }
}

public class Main2 {

    String x;

    public Main2(String x) {
        this.x = x;
        Main.x = x; // Это второй вариант но только если переменная static
    }
}

Here, to be honest, there are 2 ways due to the fact that the variable is static

Answer 3

packagefoo;
Have you heard of packages?

Answer 4

If in 1.java the static variables "x"(string), and 1 and 2 are in the same package,
then you can access the first class directly from the second class: just write in the second 1.x