If I write the following class:
public class Example {
int j;
int k;
public Example(int j, int k) {
j = j;
k = k;
You assign the parameter to itself in your example.
More generally speaking: If you don't prepend a scope to your variable, the current scope is assumed - which is the function in your case. 'this.j' tells the jre to use the variable j within the object scope - the member variable of the object.