Call By Reference Vs Call By Value

한번씩 까먹는다.
정말 기초가 중요하다.

- Call By Reference Vs Call By Value
public class PassTest { private void methodA(){ TestObject testObject = new TestObject(); testObject.attribute = "I'm A"; methodB(testObject); System.out.println("9 : " + testObject.attribute); } private void methodB(TestObject obj){ System.out.println("1 : " + obj.attribute); obj.attribute = "I'm B"; System.out.println("2 : " + obj.attribute); obj = new TestObject(); obj.attribute = "I'm b"; System.out.println("3 : " + obj.attribute); } public static void main(String[] args) { new PassTest().methodA(); } } class TestObject{ public String attribute; }

1 : I'm A
2 : I'm B
3 : I'm b
9 : I'm B

- 테스트 작성^[각주:1] public class PassTest { private static final String IamA = "I'm A"; private static final String IamB = "I'm B"; private static final String IamC = "I'm C"; @Test public void test(){ TestObject testObject = new TestObject(); testObject.attribute = IamA; assertThat(testObject.attribute, is(IamA)); call(testObject); assertThat(testObject.attribute, is(not(IamA))); assertThat(testObject.attribute, is(IamB)); assertThat(testObject.attribute, is(not(IamC))); } void call(TestObject testObject){ assertThat(testObject.attribute, is(IamA)); testObject.attribute = IamB; assertThat(testObject.attribute, is(IamB)); testObject = new TestObject(); testObject.attribute = IamC; assertThat(testObject.attribute, is(IamC)); } }

1. 2011-02-10 추가 [본문으로]