The difference between class and instance variables is also called a static variable, that is, a variable with static in front of the variable;
An instance variable is also called an object variable, that is, a variable that does not add static;
The difference is:
The difference between a class variable and an instance variable is that the class variable is common to all objects, where one object changes its value, the other object gets the changed result, and the instance variable is the object's private, and an object changes its value without affecting other objects;
Cases:
public class a{
static int a = 0; class variables
private int b = 0; Strength variable
}
public class b{
public void Main (string[] args) {
A a1 = new A ();
A a2 = new A ();
a1.a = 3; Equivalent to A.A = 3;
a1.b = 4;
System.out.println (a2.a); Result is 3
The class variable is for all objects, so A1 change a,a2 a also changes
System.out.println (a2.b); Result is 0
The instance only changes itself, so the B change of the A1 object does not affect the B variable of the object A2
}
}
The difference between a "Java" class variable and an instance variable
