1. 출력 값을 작성하시오.
class Connection {
private static Connection _inst = null;
private static int count = 0;
private static final Object lock = new Object();
private Connection() {}
static public Connection getInstance() {
synchronized (lock) {
if(_inst == null) {
_inst = new Connection();
}
return _inst;
}
}
static public synchronized void incrementCount() {
count++;
}
static public synchronized void decrementCount() {
count--;
}
static public synchronized int getCount() {
return count;
}
}
public class ConnectionTest {
public static void main(String[] args) {
Connection conn1 = Connection.getInstance();
Connection.incrementCount();
Connection conn2 = Connection.getInstance();
Connection.incrementCount();
Connection conn3 = Connection.getInstance();
Connection.incrementCount();
Connection.decrementCount();
Connection.incrementCount();
Connection.incrementCount();
Connection.incrementCount();
System.out.println("Count of conn1: " + Connection.getCount());
System.out.println("Count of conn2: " + Connection.getCount());
System.out.println("Count of conn3: " + Connection.getCount());
}
}정답
Count of conn1: 5
Count of conn2: 5
Count of conn3: 5
2. 출력 값을 작성하시오.
public class Main {
public static void main(String args[]) {
int i = 2;
int k = 5;
switch(i) {
case 1: k += 2;
case 2: k--;
case 3: k *= 2;
case 4: k /= 2;
case 5: k -= 3;
default: k++;
}
System.out.print(k);
}
}정답
2
3. 출력 값을 작성하시오.
public class Main {
static class A {
int n;
int g;
}
public static void main(String[] args) {
A[] a = new A[2];
for (int i = 0; i < 2; i++) {
a[i] = new A();
a[i].n = i;
a[i].g = i + 1;
}
System.out.println(a[0].n + a[1].g);
}
}정답
2
4. 출력 값을 작성하시오.
public class Main {
static class A {
int n;
int g;
}
public static void main(String[] args) {
A[] a = new A[8];
for (int i = 0; i < 8; i++) {
a[i] = new A();
a[i].n = i;
a[i].g = i + 1;
}
System.out.println(a[6].n + a[7].g);
}
}정답
14
5. 출력 값을 작성하시오.
public class Main
{
static void func1(A m)
{
m.a *= 10;
}
static void func2(A m)
{
m.a += m.b;
}
public static void main(String args[])
{
A m = new A();
m.a = 200;
func1(m);
m.b = m.a;
func2(m);
System.out.printf("%d", m.a);
System.out.printf("%d", m.b);
}
}정답
20004000
6. 출력 값을 작성하시오.
class Connection {
private static Connection _inst = null;
private int count = 0;
static public Connection get() {
if (_inst == null) {
_inst = new Connection();
}
return _inst;
}
public void count() {
count++;
}
public int getCount() {
return count;
}
}
public class Main {
public static void main(String[] args) {
Connection conn1 = Connection.get();
conn1.count();
System.out.println(conn1.getCount());
Connection conn2 = Connection.get();
conn2.count();
System.out.println(conn1.getCount());
Connection conn3 = Connection.get();
System.out.println(conn2.getCount());
conn3.count();
conn3.count();
System.out.print(conn1.getCount() + conn2.getCount() + conn3.getCount());
}
}정답
1
2
2
12
7. 출력 값을 작성하시오.
public class Main {
public static void main(String[] args) {
int a = 2, b = 4, c = 6, d = 8;
if ((a == 2 | a == c) & !(c > d) & (1 == b ^ c != d)) {
a = b + c;
if (7 == b ^ c != a) {
System.out.println(a);
} else {
System.out.println(b);
}
} else {
a = c + d;
if (7 == c ^ d != a) {
System.out.println(a);
} else {
System.out.println(d);
}
}
}
}정답
10
8. 출력 값을 작성하시오.
public class Main {
public static void main(String[] args) {
int i, j;
for (j = 0, i = 0; i <= 7; i++) {
j += i;
System.out.print(i);
if (i == 7) {
System.out.print("=");
System.out.println(j + i);
System.out.print(j);
} else {
System.out.print("+");
}
}
}
}정답
0+1+2+3+4+5+6+7=35
28
9. 출력 값을 작성하시오.
public class Main {
public static void main(String[] args) {
ovr1 a1 = new ovr1();
ovr2 a2 = new ovr2();
System.out.println(a1.sun(4,5) + a2.sun(3,2));
}
}
class ovr1 {
int sun(int x, int y) {
return x - y;
}
}
class ovr2 extends ovr1 {
int sun(int x, int y) {
return x + y + super.sun(x, y);
}
}정답
5
10. 출력 값을 작성하시오.
public class Main{
public static void main(String[] args){
int[][]arr = new int[][]{{45,510,35},{89,115}};
System.out.println(arr[0].length);
System.out.println(arr[1].length);
System.out.println(arr[0][0]);
System.out.println(arr[0][1]);
System.out.println(arr[1][0]);
System.out.println(arr[1][1]);
}
}정답
3
2
45
510
89
115
