# What is the identity for concatenation?

## What is the identity for concatenation?

ε is the identity for concatenation.

## How do I combine two lists?

Join Two Lists

1. Join two list: list1 = ["a", "b" , "c"] list2 = [1, 2, 3] list3 = list1 + list2. print(list3) ...
2. Append list2 into list1: list1 = ["a", "b" , "c"] list2 = [1, 2, 3] for x in list2: list1.append(x) ...
3. Use the extend() method to add list2 at the end of list1: list1 = ["a", "b" , "c"] list2 = [1, 2, 3] list1.extend(list2)

## Are two Numpy arrays equal?

array_equal. True if two arrays have the same shape and elements, False otherwise. Returns True if the arrays are equal. ...

## How does an array work?

An array is a container object that holds a fixed number of values of a single type. The length of an array is established when the array is created. After creation, its length is fixed. ... Each item in an array is called an element, and each element is accessed by its numerical index.

## How do you initiate an array?

Initializing an array

1. class HelloWorld { public static void main( String args[] ) { //Initializing array. int[] array = new int[5]; ...
2. class HelloWorld { public static void main( String args[] ) { //Array Declaration. int[] array; ...
3. class HelloWorld { public static void main( String args[] ) { int[] array = {14,15};

## What are the advantages of array?

• In an array, accessing an element is very easy by using the index number.
• The search process can be applied to an array easily.
• 2D Array is used to represent matrices.
• For any reason a user wishes to store multiple values of similar type then the Array can be used and utilized efficiently.

## What are the different types for initializing an array?

Designated Initializer: This initializer is used when we want to initialize a range with the same value. This is used only with GCC compilers. Macros: For initializing a huge array with the same value we can use macros. Using For Loop: We can also use for loop to initialize an array with the same value.

## How do you declare and initialize an array?

We declare an array in Java as we do other variables, by providing a type and name: int[] myArray; To initialize or instantiate an array as we declare it, meaning we assign values as when we create the array, we can use the following shorthand syntax: int[] myArray = {13, 14, 15};