System.out.println(\ System.out.println(\ System.out.println(\ System.out.println(\ } }
Results: x is 0 y is 6 i is 5 j is 12 f is 0.0
2.
public class Test {
public static void main(String[] args) { int i = 1;
while (i <= 5) {
int num = 1;
for (int j = 1; j <= i; j++) { System.out.print(num + \ num *= 3; }
System.out.println(); i++; } } }
Results: 1bb 1bb3bb
1bb3bb9bb
1bb3bb9bb27bb 1bb3bb9bb27bb81bb
3.
public class Test {
public static void main(String[] args) {
int i = 1;
while (i <= 5) {
第 25 页 共 34 页
xMethod(i); i++; } }
public static void xMethod(int i) { int num = 1;
for (int j = 1; j <= i; j++) { System.out.print(num + \ num *= 3; }
System.out.println(); } }
Results: 1 1 3 1 3 9 1 3 9 27 1 3 9 27 81
4.
public class Test {
public static void main(String[] args) {
int i = 1;
while (i <= 5) { xMethod(i); i++; } }
public static void xMethod(int i) { do {
if (i % 2 != 0)
System.out.print(i + \ i--;
}while (i >= 1);
System.out.println(); } }
第 26 页 共 34 页
Results: 1 1 3 1 3 1 5 3 1
5.
public class Test {
public static void main(String[] args) { xMethod(4); }
public static void xMethod(int i) { if (i > 0) {
System.out.println(i); xMethod(--i); } } }
Results: 4 3 2 1
6.
public class Test {
public static void main(String[] args) { int[] a = {1, 2};
System.out.println(\
System.out.println(\ swap(a[0], a[1]);
System.out.println(\
System.out.println(\ }
public static void swap(int n1, int n2) { int temp = n1; n1 = n2; n2 = temp;
第 27 页 共 34 页
}
}
Results:
Before swapping: a[0] = 1 a[1] = 2 After swapping: a[0] = 1 a[1] = 2
7.
public class Test {
public static void main(String[] args){ int[] a = {1, 2};
System.out.println(\
System.out.println(\ swap(a);
System.out.println(\
System.out.println(\ }
public static void swap(int[] a){ int temp = a[0]; a[0] = a[1]; a[1] = temp; } }
Results:
Before swapping: a[0] = 1 a[1] = 2 After swapping: a[0] = 2 a[1] = 1
8.
public class Test {
public static void main(String[] args) {
int[] x = {1, 2, 3, 4, 5}; increase(x);
int[] y = {1, 2, 3, 4, 5}; increase(y[0]);
System.out.println(x[0] + \
第 28 页 共 34 页