Tutorial by Examples: num

public class Singleton { private static final Singleton INSTANCE = new Singleton(); private Singleton() {} public static Singleton getInstance() { return INSTANCE; } } It can be argued that this example is effectively lazy initialization. Section 12.4.1 of ...

The Switch statement works very well with Enum values enum CarModel { case Standard, Fast, VeryFast } let car = CarModel.Standard switch car { case .Standard: print("Standard") case .Fast: print("Fast") case .VeryFast: print("VeryFast") } Since we ...

From MSDN: An enumeration type (also named an enumeration or an enum) provides an efficient way to define a set of named integral constants that may be assigned to a variable. Essentially, an enum is a type that only allows a set of finite options, and each option corresponds to a number. By d...

Create a DataFrame of random numbers: import numpy as np import pandas as pd # Set the seed for a reproducible sample np.random.seed(0) df = pd.DataFrame(np.random.randn(5, 3), columns=list('ABC')) print(df) # Output: # A B C # 0 1.764052 0.400157 0.9787...

A major problem with parallelization is the used of RNG as seeds. Random numbers by the number are iterated by the number of operations from either the start of the session or the most recent set.seed(). Since parallel processes arise from the same function, it can use the same seed, possibly causin...

Our randomNumbers() function can be re-written to use a generator. <?php function randomNumbers(int $length) { for ($i = 0; $i < $length; $i++) { // yield tells the PHP interpreter that this value // should be the one used in the current iteration. yield mt...

When writing a class with generics in java, it is possible to ensure that the type parameter is an enum. Since all enums extend the Enum class, the following syntax may be used. public class Holder<T extends Enum<T>> { public final T value; public Holder(T init) { t...

The FlagsAttribute should be used whenever the enumerable represents a collection of flags, rather than a single value. The numeric value assigned to each enum value helps when manipulating enums using bitwise operators. Example 1 : With [Flags] [Flags] enum Colors { Red=1, Blue=2, ...

If I wanted to find out the sum of numbers from 1 to n where n is a natural number, I can do 1 + 2 + 3 + 4 + ... + (several hours later) + n. Alternatively, I could write a for loop: n = 0 for i in range (1, n+1): n += i Or I could use a technique known as recursion: def recursion(n): ...

extern crate serde; extern crate serde_json; macro_rules! enum_str { ($name:ident { $($variant:ident($str:expr), )* }) => { #[derive(Clone, Copy, Debug, Eq, PartialEq)] pub enum $name { $($variant,)* } impl ::serde::Serialize for $name {...

Say we have an enum DayOfWeek: enum DayOfWeek { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY; } An enum is compiled with a built-in static valueOf() method which can be used to lookup a constant by its name: String dayName = DayOfWeek.SUNDAY.name(); assert dayName.equal...

Enum constants are instantiated when an enum is referenced for the first time. Therefore, that allows to implement Singleton software design pattern with a single-element enum. public enum Attendant { INSTANCE; private Attendant() { // perform some initialization routine ...

Elixir comes with integers and floating point numbers. An integer literal can be written in decimal, binary, octal and hexadecimal formats. iex> x = 291 291 iex> x = 0b100100011 291 iex> x = 0o443 291 iex> x = 0x123 291 As Elixir uses bignum arithmetic, the range of int...

The Number constructor has some built in constants that can be useful Number.MAX_VALUE; // 1.7976931348623157e+308 Number.MAX_SAFE_INTEGER; // 9007199254740991 Number.MIN_VALUE; // 5e-324 Number.MIN_SAFE_INTEGER; // -9007199254740991 Number.EPSILON; // 0.000...

Returns a random integer between min and max: function randomBetween(min, max) { return Math.floor(Math.random() * (max - min + 1) + min); } Examples: // randomBetween(0, 10); Math.floor(Math.random() * 11); // randomBetween(1, 10); Math.floor(Math.random() * 10) + 1; // randomBet...

Boolean(0) === false Boolean(0) will convert the number 0 into a boolean false. A shorter, but less clear, form: !!0 === false

An enum is a set of logically related constants. Enum Size Small Medium Large End Enum Public Sub Order(shirtSize As Size) Select Case shirtSize Case Size.Small ' ... Case Size.Medium ' ... Case Size.Large ' ....

For the following DataFrame: import numpy as np import pandas as pd np.random.seed(0) df = pd.DataFrame({'Age': np.random.randint(20, 70, 100), 'Sex': np.random.choice(['Male', 'Female'], 100), 'number_of_foo': np.random.randint(1, 20, 100)}) df.head() ...

public string Remove() { string input = "Hello./!"; return Regex.Replace(input, "[^a-zA-Z0-9]", ""); }

If you want to parse a String to enum with Gson: {"status" : "open"} public enum Status { @SerializedName("open") OPEN, @SerializedName("waiting") WAITING, @SerializedName("confirm") CONFIRM, @SerializedName(&...