1
I do not understand why the program displays, in the last System.out.print, that:
2 5 2 4 6 8 10
Instead:
5 2 5 10 15 20 25
The first method, trocaB, should not change the values of the variables a and b?
public class Java {
public static void trocaB(String a, String b){
String tmp = a;
a = b;
b = tmp;
}
public static void trocaC(int[] array, String a){
for (int x = 0; x < array.length; x++){
array[x] = array[x] * Integer.valueOf(a);
}
}
public static void main(String[] args){
int[] array = {1,2,3,4,5};
String a = "2", b="5";
trocaB(a, b);
trocaC(array,a);
System.out.print(a + " " + b + " ");
for (int x = 0; x < array.length; x++) {
System.out.print(array[x] + " ");
}
}
}
Gentlemen(s), forgive me the stupid question, I’m still learning Java. I deeply appreciate you helping me with the links. I understood that the values of strings are immutable and that complex variables store addresses of the objects to which they are referenced. However, in the trocaB method, I say that the complex variable A, from that moment on, will refer to the complex variable B. Why doesn’t the value of A change? This should not make the variable Saving a new address?
– Rafael Barbosa
Read this answer, especially the final part about Java that says references are passed by value. Highlight for the last paragraph: "references themselves are independent of each other. They are copies of each other. And tampering with a copy doesn’t change the original"
– hkotsubo