Helper Class es una clase de Java que incluye el manejo básico de errores, algunas funciones auxiliares, etc. La clase Helper contiene funciones que ayudan a ayudar al programa. Esta clase tiene la intención de brindar una implementación rápida de funciones básicas para que los programadores no tengan que implementarlas una y otra vez. Es fácil de acceder ya que todas las funciones de los miembros son estáticas, es decir, se puede acceder desde cualquier lugar. Implementa las funciones más utilizadas excluyendo las funciones que ya están presentes en la biblioteca Java.
Las diferentes clases auxiliares contienen diferentes métodos dependiendo de la necesidad del programa.
Recomendación: haga un paquete para esta clase nombrando HelperClass e impórtelo en su código Java
A continuación se muestra un ejemplo de clase de ayuda.
// Example for helper class
import java.lang.*;
import java.util.*;
class HelperClass {
// to check whether integer is greater than 0 or not
// usually used when we have to input a whole number
// like taking input of number of test cases etc
public static boolean isValidInteger(int test)
{
return (test >= 0);
}
// to check whether integer is greater than the lower
// bound and lower than the highest bound.
public static boolean isValidInteger(int test, int low,
int high) {
return (test >= low && test <= high);
}
// used when we want the user to input the number
// exactly greater than the lower bound
public static int getInRange(int low) {
Scanner sc = new Scanner(System.in);
int test;
do
{
test = sc.nextInt();
} while (test < low);
return test;
}
// used when we want the user to input the number
// exactly greater than lower bound and lower than
// the highest bound
public static int getInRange(int low, int high) {
Scanner sc = new Scanner(System.in);
int test;
do {
test = sc.nextInt();
} while (test < low || test > high);
return test;
}
// to check whether an array contains any negative value
public static boolean validatePositiveArray(int[] array,
int n) {
for (int i = 0; i < n; i++)
if (array[i] < 0)
return false;
return true;
}
// to check whether an array contains any positive value
public static boolean validateNegativeArray(int[] array,
int n) {
for (int i = 0; i < n; i++)
if (array[i] > 0)
return false;
return true;
}
// check whether every element in the array is greater
// than the lower bound
public static boolean checkRangeArray(int[] array,
int n, int low) {
for (int i = 0; i < n; i++)
if (array[i] < low)
return false;
return true;
}
// check whether every element in the array is greater
// than the lower bound and lower than the highest bound
public static boolean checkRangeArray(int[] array, int n,
int low, int high) {
for (int i = 0; i < n; i++)
if (array[i] < low || array[i] > high)
return false;
return true;
}
// check whether two given sets as "arrays" are equal or not
public static boolean isEqualSets(int[] array1, int n,
int[] array2, int m) {
if (n != m)
return false;
HashMap<Integer, Integer> Map =
new HashMap<Integer, Integer>();
for (int i = 0; i < n; i++)
Map.put(new Integer(array1[i]), new Integer(1));
for (int i = 0; i < m; i++)
Map.put(new Integer(array2[i]), new Integer(0));
for (int i = 0; i < n; i++)
if (Map.get(array1[i]) == 1)
return false;
return true;
}
// calculating factorial of a number
public static String factorial(int n) {
String fact = new String("");
int res[] = new int[500];
res[0] = 1;
int res_size = 1;
for (int x = 2; x <= n; x++)
res_size = multiply(x, res, res_size);
for (int i = res_size - 1; i >= 0; i--)
fact += Integer.toString(res[i]);
return fact;
}
// Multiply x with res[0..res_size-1]
public static int multiply(int x, int res[], int res_size) {
int carry = 0;
for (int i = 0; i < res_size; i++) {
int prod = res[i] * x + carry;
res[i] = prod % 10;
carry = prod / 10;
}
while (carry != 0) {
res[res_size] = carry % 10;
carry = carry / 10;
res_size++;
}
return res_size;
}
// Checks whether the given number is prime or not
public static boolean isPrime(int n) {
if (n == 2)
return true;
int squareRoot = (int)Math.sqrt(n);
for (int i = 1; i <= squareRoot; i++)
if (n % i == 0 && i != 1)
return false;
return true;
}
// Returns nthPrimeNumber
public static int nthPrimeNumber(int n) {
int k = 0;
for (int i = 2;; i++) {
if (isPrime(i))
k++;
if (k == n)
return i;
}
}
// check whether the given string is palindrome or not
public static boolean isPalindrome(String test) {
int length = test.length();
for (int i = 0; i <= (test.length()) / 2; i++)
if (test.charAt(i) != test.charAt(length - i - 1))
return false;
return true;
}
// check whether two strings are anagram or not
public static boolean isAnagram(String s1, String s2) {
// Removing all white spaces from s1 and s2
String copyOfs1 = s1.replaceAll("\\s", "");
String copyOfs2 = s2.replaceAll("\\s", "");
if (copyOfs1.length() != copyOfs2.length())
return false;
// Changing the case of characters of both copyOfs1 and
// copyOfs2 and converting them to char array
char[] s1Array = copyOfs1.toLowerCase().toCharArray();
char[] s2Array = copyOfs2.toLowerCase().toCharArray();
// Sorting both s1Array and s2Array
Arrays.sort(s1Array);
Arrays.sort(s2Array);
// Checking whether s1Array and s2Array are equal
return (Arrays.equals(s1Array, s2Array));
}
} /*** end of helperClass **/
class Test {
public static void main(String[] args) {
int n = -5;
if (HelperClass.isValidInteger(n))
System.out.println("True");
else
System.out.println("False");
String str = "madam";
if (HelperClass.isPalindrome(str))
System.out.println("True");
else
System.out.println("False");
}
}
False True
Publicación traducida automáticamente
Artículo escrito por sahilkhoslaa y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA