AlphaCodingSkills

NumPy stands for Numerical Python, is a library for the Python programming language. It provides support for large, multi-dimensional arrays and matrices, along with a large collection of routines for fast operations on arrays. It is a open-sourced software and has many contributors.

Java.util package provides a Arrays class which contains a static factory that allows arrays to be viewed as lists. The class contains various methods for manipulating arrays like sorting and searching. The methods in this class throw a NullPointerException, if the specified array reference is null.

Java.lang package provides a Long class which wraps a value of the primitive type long in an object. An object of type Long contains a single field whose type is long.

In addition, this class provides several methods for converting a long to a String and a String to a long, as well as other constants and methods useful when dealing with a long.

Java.lang package provides a Integer class which wraps a value of the primitive type int in an object. An object of type Integer contains a single field whose type is int.

In addition, this class provides several methods for converting an int to a String and a String to an int, as well as other constants and methods useful when dealing with an int.

Java.lang package provides a Number class which is a abstract class and it is the superclass of platform classes representing numeric values that are convertible to the primitive types byte, double, float, int, long, and short.

Java.lang package provides a Enum class which is the common base class of all Java language enumeration types.

Java.lang package provides a Short class which wraps a value of primitive type short in an object. An object of type Short contains a single field whose type is short.

In addition, this class provides several methods for converting a short to a String and a String to a short, as well as other constants and methods useful when dealing with a short.

Java.lang package provides a Boolean class which wraps a value of the primitive type boolean in an object. An object of type Boolean contains a single field whose type is boolean.

In addition, this class provides many methods for converting a boolean to a String and a String to a boolean, as well as other constants and methods useful when dealing with a boolean.

Java.lang package provides a Float class which wraps a value of primitive type float in an object. An object of type Float contains a single field whose type is float.

In addition, this class provides several methods for converting a float to a String and a String to a float, as well as other constants and methods useful when dealing with a float.

Java.lang package provides a Double class which wraps a value of the primitive type double in an object. An object of type Double contains a single field whose type is double.

In addition, this class provides several methods for converting a double to a String and a String to a double, as well as other constants and methods useful when dealing with a double.

Java.lang package provides a Byte class which wraps a value of primitive type byte in an object. An object of type Byte contains a single field whose type is byte.

In addition, this class provides several methods for converting a byte to a String and a String to a byte, as well as other constants and methods useful when dealing with a byte.

Java.lang package provides a Math class which contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.

Java.lang package provides a StrictMath class which contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.

Java.lang package provides a String class which represents character strings. All string literals in Java programs, such as "xyz", are implemented as instances of this class. Strings are constant; their values cannot be changed after they are created.

Java.util package provides a IdentityHashMap class which implements the Map interface with a hash table, using reference-equality in place of object-equality when comparing keys (and values). In other words, in an IdentityHashMap, two keys k1 and k2 are considered equal if and only if (k1==k2). (In normal Map implementations (like HashMap) two keys k1 and k2 are considered equal if and only if (k1==null ? k2==null : k1.equals(k2)).)

Java.util package provides a TreeSet class which is a NavigableSet implementation based on a TreeMap. The elements are ordered using their natural ordering, or by a Comparator provided at set creation time, depending on which constructor is used. The class guarantees that the Map will be in ascending key order and backed by a TreeMap.

Java.util package provides a EnumSet class which is a specialized Set implementation for use with enum types. All of the elements in an enum set must come from a single enum type that is specified, explicitly or implicitly, when the set is created. Enum sets are represented internally as bit vectors. This representation is extremely compact and efficient. Null elements are not permitted. Attempts to insert a null element will throw NullPointerException.

Java.util package provides a Calendar class which represents a specific instant in time, with millisecond precision.

Java.util package provides a GregorianCalendar class which is a concrete subclass of Calendar and provides the standard calendar system used by most of the world.

Java.util package provides a Random class. An instance of this class is used to generate a stream of pseudorandom numbers. The class uses a 48-bit seed, which is modified using a linear congruential formula. The algorithms implemented by class Random use a protected utility method that on each invocation can supply up to 32 pseudorandomly generated bits.

Java.util package provides a Date class which represents a specific instant in time, with millisecond precision.

Java.util package provides a UUID class which represents an immutable universally unique identifier (UUID). A UUID represents a 128-bit value. It is used for for creating random file names, session id in web application, transaction id etc. There are four different basic types of UUIDs: time-based, DCE security, name-based, and randomly generated UUIDs.

Java.util package provides a Dictionary class which is the abstract parent of any class, such as Hashtable, which maps keys to values. Every key and every value is an object. In any one Dictionary object, every key is associated with at most one value. Given a Dictionary and a key, the associated element can be looked up. Any non-null object can be used as a key and as a value.

A Hashtable models and implements the Map interface. This implementation provides all of the optional map operations, and permits null values and the null key. A HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls. This class makes no guarantees as to the order of the map. It does not guarantee that the order will remain constant over time.

A Hashtable models and implements the Map interface. This implementation provides all of the optional map operations, and permits null values and the null key. A HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls. This class makes no guarantees as to the order of the map. It does not guarantee that the order will remain constant over time.

Java.util package provides a EnumMap class which is a specialized Map implementation for use with enum type keys. All of the keys in an enum map must come from a single enum type that is specified, explicitly or implicitly, when the map is created.

Java.util package provides a Hashtable class which implements hash table and maps keys to value. Any non-null object can be used as a key or as a value. To successfully store and retrieve objects from a hashtable, the objects used as keys must implement the hashCode method and the equals method.

A HashSet class implements the Set interface, backed by the a Hashtable interface (actually a HashMap instance). This class makes no guarantees as to the iteration order of the set. It does not guarantee that the order will remain constant over time. The class permits the null element.

Java.util package provides a Scanner class. A simple text scanner parse primitive types and strings using regular expressions. A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. The resulting tokens may then be converted into values of different types using the various next methods.

Java.util package provides a vector class which models and implements vector data structure. A vector is a sequence container implementing array that can change in size. Unlike array, the size of a vector changes automatically when elements are appended or deleted. It is similar to ArrayList, but with two differences:

Vector is synchronized.
Vector contains many legacy methods that are not part of the collections framework.