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© 2001 by Tom Swan. All rights reserved.
Updated: 6/4/01 12:20:54 PM
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001: class ArrayBounds { 002: public static void main(String args[]) { 003: int intArray[] = new int[10]; // Create array 004: try { 005: int q = intArray[5]; // no error 006: int p = intArray[11]; // throws exception 007: } catch (ArrayIndexOutOfBoundsException e) { 008: System.out.println("Array index out of bounds"); 009: } 010: } 011: }Return to top
001: class Triangle { 002: public static void main(String args[]) { 003: // Create a triangular array 004: int triangular[][]; 005: triangular = new int[8][]; 006: for (int i = 0; i < triangular.length; i++) 007: triangular[i] = new int[i + 1]; 008: 009: // Assign values at random to the array 010: for (int i = 0; i < triangular.length; i++) 011: for (int j = 0; j < triangular[i].length; j++) 012: triangular[i][j] = (int)(Math.random() * 100); 013: 014: // Display the array's contents 015: for (int i = 0; i < triangular.length; i++) { 016: for (int j = 0; j < triangular[i].length; j++) 017: System.out.print(" /t" + triangular[i][j]); 018: System.out.println(); 019: } 020: } 021: }Return to top
001: class StringClass { 002: private String s; 003: // Constructor 004: StringClass(String s) { 005: this.s = s; 006: } 007: void ShowString() { 008: System.out.println(s); 009: } 010: } 011: 012: class ObjectArray { 013: public static void main(String args[]) { 014: // Construct an array of class objects 015: StringClass WeekDays[] = { 016: new StringClass("Domingo"), 017: new StringClass("Lunes"), 018: new StringClass("Martes"), 019: new StringClass("Miercoles"), 020: new StringClass("Jueves"), 021: new StringClass("Viernes"), 022: new StringClass("Sabado") 023: }; 024: // Call a method for each arrayed object 025: System.out.println("Weekdays in Spanish"); 026: for (int i = 0; i < WeekDays.length; i++) 027: WeekDays[i].ShowString(); 028: } 029: }Return to top
001: import TestClass; // Import submodule 002: 003: class ArrayCopy { 004: // Declare the two arrays 005: public static int[] apples, oranges; 006: 007: // Array copy method #1 008: public static void CopyMethod1() { 009: System.out.println("/nArray copy method #1"); 010: oranges = apples; 011: // oranges[0]++; // Enable to change test 012: TestClass.CompareArrays(apples, oranges); 013: } 014: 015: // Array copy method #2 016: public static void CopyMethod2() { 017: System.out.println("/nArray copy method #2"); 018: oranges = new int[apples.length]; 019: System.arraycopy(apples, 0, oranges, 0, apples.length); 020: oranges[0]++; // Enable to change test 021: TestClass.CompareArrays(apples, oranges); 022: } 023: 024: // Array copy method #3 025: public static void CopyMethod3() { 026: System.out.println("/nArray copy method #3"); 027: oranges = (int[])apples.clone(); 028: // oranges[0]++; // Enable to change test 029: TestClass.CompareArrays(apples, oranges); 030: } 031: 032: public static void main(String args[]) { 033: // Construct and initialize the first array 034: apples = new int[8]; 035: for (int i = 0; i < apples.length; i++) 036: apples[i] = (int)(Math.random() * 100); 037: // Copy three ways and test each copy 038: CopyMethod1(); 039: CopyMethod2(); 040: CopyMethod3(); 041: } 042: }Return to top
001: class TestClass { 002: public static void CompareArrays(int apples[], int oranges[]) 003: { 004: // Display the array values 005: int i; 006: System.out.print("apples : "); 007: for (i = 0; i < apples.length; i++) 008: System.out.print(apples[i] + " /t"); 009: System.out.print("/noranges: "); 010: for (i = 0; i < oranges.length; i++) 011: System.out.print(oranges[i] + " /t"); 012: System.out.println(); // Start new line 013: 014: // Test if the array references are the same 015: if (apples == oranges) 016: System.out.println("Array references are identical"); 017: else 018: System.out.println("Array references are NOT identical"); 019: 020: // Test if the array contents are the same 021: boolean identical = true; 022: for (i = 0; i < apples.length; i++) 023: if (apples[i] != oranges[i]) 024: identical = false; 025: if (identical) 026: System.out.println("Array contents are the same"); 027: else 028: System.out.println("Array contents are NOT the same"); 029: } 030: }Return to top
001: // Arrays class sorting methods 002: public static void sort(long[] a); 003: public static void sort(long[] a, int fromIndex, int toIndex); 004: public static void sort(int[] a); 005: public static void sort(int[] a, int fromIndex, int toIndex); 006: public static void sort(short[] a); 007: public static void sort(short[] a, int fromIndex, int toIndex); 008: public static void sort(char[] a); 009: public static void sort(char[] a, int fromIndex, int toIndex); 010: public static void sort(byte[] a); 011: public static void sort(byte[] a, int fromIndex, int toIndex); 012: public static void sort(double[] a); 013: public static void sort(double[] a, int fromIndex, int toIndex); 014: public static void sort(float[] a); 015: public static void sort(float[] a, int fromIndex, int toIndex); 016: public static void sort(Object[] a); 017: public static void sort(Object[] a, int fromIndex, int toIndex); 018: public static void sort(Object[] a, Comparator c); 019: public static void sort(Object[] a, int fromIndex, int toIndex, Comparator c);Return to top
001: import java.util.Arrays; 002: 003: class SortStrings { 004: // Display an array of Strings 005: public static void ShowStrings(String[] a, String msg) { 006: System.out.println(msg); 007: for (int i = 0; i < a.length; i++) 008: System.out.println(a[i]); 009: } 010: // Create, sort, and display an array of StringClass objects 011: public static void main(String args[]) { 012: String colors[] = { 013: "rojo", "azul", "verde", "negro", "blanco", "cafe", "gris" 014: }; 015: ShowStrings(colors, "/nBefore sorting"); 016: Arrays.sort(colors); 017: ShowStrings(colors, "/nAfter sorting"); 018: } 019: }Return to top
001: import java.util.Arrays; 002: 003: class StringClass implements Comparable { 004: private String s; 005: StringClass(String s) { 006: this.s = s; 007: } 008: void ShowString() { 009: System.out.println(s); 010: } 011: public int compareTo(Object other) { 012: StringClass sc = (StringClass)other; 013: return s.compareTo(sc.s); 014: } 015: } 016: 017: class SortObjects { 018: 019: // Display an array of StringClass objects 020: public static void ShowStrings(StringClass[] a, String msg) { 021: System.out.println(msg); 022: for (int i = 0; i < a.length; i++) 023: a[i].ShowString(); 024: } 025: 026: // Create, sort, and display an array of StringClass objects 027: public static void main(String args[]) { 028: StringClass colors[] = { 029: new StringClass("rojo"), 030: new StringClass("azul"), 031: new StringClass("verde"), 032: new StringClass("negro"), 033: new StringClass("blanco"), 034: new StringClass("cafe"), 035: new StringClass("gris") 036: }; 037: ShowStrings(colors, "/nBefore sorting"); 038: Arrays.sort(colors); 039: ShowStrings(colors, "/nAfter sorting"); 040: } 041: }Return to top
001: import java.util.Arrays; 002: import java.util.Comparator; 003: 004: // Class that implements the Comparator interface 005: class StringCompare implements Comparator { 006: public int compare(Object o1, Object o2) { 007: String s1 = (String)o1; 008: String s2 = (String)o2; 009: return s1.compareTo(s2); 010: } 011: } 012: 013: class SortComparator { 014: // Display an array of Strings 015: public static void ShowStrings(String[] a, String msg) { 016: System.out.println(msg); 017: for (int i = 0; i < a.length; i++) 018: System.out.println(a[i]); 019: } 020: // Create, sort, and display an array of StringClass objects 021: public static void main(String args[]) { 022: String colors[] = { 023: "rojo", "azul", "verde", "negro", "blanco", "cafe", "gris" 024: }; 025: ShowStrings(colors, "/nBefore sorting"); 026: // Construct the Comparator object 027: StringCompare CompareObject = new StringCompare(); 028: // Sort the array using the Comparator object 029: Arrays.sort(colors, CompareObject); 030: ShowStrings(colors, "/nAfter sorting"); 031: } 032: }Return to top
001: // Arrays class searching methods 002: public static int binarySearch(long[] a, long key); 003: public static int binarySearch(int[] a, int key); 004: public static int binarySearch(short[] a, short key); 005: public static int binarySearch(char[] a, char key); 006: public static int binarySearch(byte[] a, byte key); 007: public static int binarySearch(double[] a, double key); 008: public static int binarySearch(float[] a, float key); 009: public static int binarySearch(Object[] a, Object key); 010: public static int binarySearch(Object[] a, Object key, Comparator c);Return to top
001: // Arrays class equality testing methods 002: public static boolean equals(long[] a, long[] a2); 003: public static boolean equals(int[] a, int[] a2); 004: public static boolean equals(short[] a, short a2[]); 005: public static boolean equals(char[] a, char[] a2); 006: public static boolean equals(byte[] a, byte[] a2); 007: public static boolean equals(boolean[] a, boolean[] a2); 008: public static boolean equals(double[] a, double[] a2); 009: public static boolean equals(float[] a, float[] a2); 010: public static boolean equals(Object[] a, Object[] a2);Return to top
001: // Arrays class filling methods 002: public static void fill(long[] a, long val); 003: public static void fill(long[] a, int fromIndex, int toIndex, long val); 004: public static void fill(int[] a, int val); 005: public static void fill(int[] a, int fromIndex, int toIndex, int val); 006: public static void fill(short[] a, short val); 007: public static void fill(short[] a, int fromIndex, int toIndex, short val); 008: public static void fill(char[] a, char val); 009: public static void fill(char[] a, int fromIndex, int toIndex, char val); 010: public static void fill(byte[] a, byte val); 011: public static void fill(byte[] a, int fromIndex, int toIndex, byte val); 012: public static void fill(boolean[] a, boolean val); 013: public static void fill(boolean[] a, int fromIndex, int toIndex, boolean val); 014: public static void fill(double[] a, double val); 015: public static void fill(double[] a, int fromIndex, int toIndex,double val); 016: public static void fill(float[] a, float val); 017: public static void fill(float[] a, int fromIndex, int toIndex, float val); 018: public static void fill(Object[] a, Object val); 019: public static void fill(Object[] a, int fromIndex, int toIndex,Object val);Return to top
001: // Arrays class List methods 002: public static List asList(Object[] a); 003: public int size(); 004: public Object[] toArray(); 005: public Object get(int index); 006: public Object set(int index, Object element); 007: public int indexOf(Object o); 008: public boolean contains(Object o);Return to top
001: import java.util.Arrays; 002: import java.util.List; 003: 004: class ArraysList { 005: public static void main(String args[]) { 006: // Create array of strings 007: String fruits[] = { 008: "apple", "banana", "cherry", "pear" 009: }; 010: // Convert array to a List object 011: List fruitList = Arrays.asList(fruits); 012: // Call various List methods for the array 013: int size = fruitList.size(); 014: System.out.println("List size = " + size); 015: String s = (String)fruitList.get(2); 016: System.out.println("List element #2 = " + s); 017: if (fruitList.contains("banana")) 018: System.out.println("fruitList contains banana"); 019: } 020: }Return to top