Array Methods

Built-in array methods in computer programming provide a wide range of functionalities for manipulating arrays efficiently and effectively. These methods include operations such as adding or removing elements, searching for specific values, sorting arrays, and iterating over array elements. Methods like push(), pop(), shift(), and unshift() allow developers to add or remove elements from the beginning or end of an array, while splice() enables more flexible insertion and deletion of elements at specific positions. Additionally, methods like indexOf(), includes(), and find() aid in searching for values within arrays, providing efficient ways to determine the presence or location of specific elements. Overall, built-in array methods streamline common array operations, improve code readability, and enhance developer productivity by providing convenient and optimized solutions for array manipulation tasks in computer programming.

Select Languages

Examples

C

// No Built in methods in C arrays

C#

List<string> cars = new List<string>();
cars.Add("Honda");
cars.Add("Mazda");
cars.Add("Toyota");

// check existence of key Mazda
Console.WriteLine(cars.Contains("Mazda"));

// removes item at index 1
Console.WriteLine(cars[1] );
cars.RemoveAt(1);
Console.WriteLine(cars[1] );

// removes elements with matching balue 
cars.Remove("Honda");
Console.WriteLine(cars[0]);

// count number of elements
Console.WriteLine(cars.Count);

C++

#include <iostream>
#include <vector>
using namespace std;

vector<string> cars = {"Honda", "Mazda", "Toyota"};
  
// 3 elements in vector
cout << cars.size() << endl;

// Mazda is at index 1
cout << cars.at(1) << endl;

// 1st element is Honda
cout << cars.front() << endl;

// last element is Toyota
cout << cars.back() << endl;

// replaces entire vector with two Fords
cars.assign(2, "Ford");
cout << cars[0] << endl;
cout << cars[1] << endl;

// add Tesla at the end of vector
cars.push_back("Tesla"); 
cout << cars.back() << endl;

// removes last element Tesla
cars.pop_back();
cout << cars.back() << endl;

// inserts Honda at front of vector
cars.insert(0, "Honda");
cout << cars.front() << endl;

Go

cars := []string {"Honda","Mazda","Toyota"}

// number of elements
fmt.Println(len(cars)) 

// sliced from index 1 to 2
slicedCars := cars[1: 2]
fmt.Println(slicedCars[0]) 

// adds new element to end
cars = append(cars, "Ford")
fmt.Println(cars[3])

// removes first element
cars = cars[1:];
fmt.Println(cars);

// removes last element
cars = cars[:len(cars) - 1];
fmt.Println(cars);

Java

import java.util.ArrayList;

// adds a new element
ArrayList<String> cars = new ArrayList<>();
cars.add("Honda");
cars.add("Mazda");
cars.add("Toyota");

// total number of element
int initLength = cars.size();
System.out.println(initLength );

// get element at index one
String secondCar = cars.get(1);
System.out.println(secondCar );

// removes element one
cars.remove(1);
System.out.println(cars.get(1) );

// becomes empty
cars.clear();
System.out.println(cars.size());

JavaScript

const cars = ['Honda', 'Mazda', 'Toyota'];

// creates new array to newlist from index 1
const newList = cars.slice(1);
console.log(newList);

// cuts original list at index 1 to returnVal
const returnVal = cars.splice(1);
console.log(returnVal);
console.log(cars);

// add Ford to end of array
cars.push('Ford');
console.log(cars);

// removes last element Ford from array
cars.pop();
console.log(cars);

// adds Kia to beginning of array
cars.unshift('Kia');
console.log(cars);

// removes first element of array Kia
cars.shift();
console.log(cars);

// sorts array in alphabetical order
cars.sort();
console.log(cars);

Kotlin

val cars =
  mutableListOf<String>("Honda", "Mazda", "Toyota");
  
// number of elements
println(cars.count())

// print value at index 1
println(cars[1])

// last index number
println("${cars.lastIndex}\n")

// removes element at index 1
cars.removeAt(1);
println(cars[1]);

// clears entire list
cars.clear();
println("${cars}\n");

// checks if list empty
println(cars.isEmpty());

MatLab

cars = ["Honda", "Mazda", "Toyota"];

% number of elements
disp(numel(cars));

% checks to see that array is not empty
disp(isempty(cars));

% last elment of array
disp(cars(end));

% adds Ford to end of cars
cars = [cars, "Ford"];

% sorts the array
cars = sort(cars);
disp(cars);

% removes the last element
cars(1)=[];
disp(cars(numel(cars) - 1));

% remove the first element
cars(end)=[];
disp(cars(1));

PHP

$cars = array("Honda", "Mazda", "Toyota");

// slices from index 1 which starts new array
$newList = array_slice($cars, 1);
echo $newList[0]."\n";
echo $cars[0]."\n";

// inserts value to end of array
array_push($cars, "Ford");
echo $cars[count($cars) - 1]."\n";

// removes last element of array
array_pop($cars);
echo $cars[count($cars) - 1]."\n";

// inserts value to beginning of array
array_unshift($cars, "Kia");
echo $cars[0]."\n";

// removes first element of array
array_shift($cars);
echo $cars[0]."\n\n";

// sorts values in alphabetical order
sort($cars);
for ($i = 0; $i < count($cars); $i++) {
  echo $cars[$i]." ";
}

Python

cars = ['Honda', 'Mazda', 'Toyota']

// number of elements
initLength = len(cars)
print(initLength)

// removes element at index one
cars.pop(1)
print(cars[1])

// adds element at end
cars.append('Tesla')
print(cars[2])

// removes element with Tesla
cars.remove('Tesla')
print(len(cars))

// reverses current order of elements
cars.reverse()
print(cars)

R

cars <- list("Honda", "Mazda", "Toyota")

# number of array elements
print(length(cars))

# check to see that element is in array
print("Mazda" %in% cars)

# remove the numbered element
cars[-1]
print(cars[1])

# add Ford to array
append(cars, "Ford")
print(cars[3])

Ruby

cars = ["Honda", "Mazda", "Toyota"];

# number of elements in array
puts cars.length

# first element of array
puts cars.first

# last element of array
puts cars.last

# new array with first 2 elements
array1 = cars.take(2)
puts array1

# drops the 1st element from array
array2 = cars.drop(1)
puts array2

# removes the first element
cars.shift()
puts cars.first

# adds as new first element 
cars.unshift("Ford")
puts cars.first

# deletes at index 0
cars.delete_at(0)
puts cars.first

# checks for value Mazda
puts cars.include?("Mazda")

Rust

let mut cars = ["Honda", "Mazda", "Toyota"];

// array with 2nd to 3rd element
let sliced = &cars[1..3];
println!("{}", sliced[0]);

//checks if mazda is in array 
let check = "Mazda";
println!("{}", cars.contains(&check));

// checks numbers of element in array
println!("{}", cars.len());

// first element of array
println!("{:?}", cars.first_mut());

// last element of array
println!("{:?}", cars.last_mut());

// get element by index no
println!("{:?}", cars.get_mut(1));

Scala

// lists in Scala are not mutable 
val cars = List("Honda", "Mazda", "Toyota");

// number of element in array
println(cars.length);

// drops first 2 elements
val array1 = cars.drop(2);
println(array1);

// checks array to see that Mazda exists
println(cars.contains("Mazda"));

// checks to see that list is not empty
println(cars.isEmpty);

Swift

var cars = ["Honda", "Mazda", "Toyota"];

// adds element ot end of aray
cars.append("Ford");
print(cars);

// check to see if element exists in arrayu
print(cars.contains("Ford"));

// removes first element
var array1 = cars.dropFirst();
print(array1);

// removes second element
var array2 = cars.dropLast();
print(array2);

// inserts element at index 1
cars.insert("Ford", at: 1)
print(cars);

// removes element at index 1
cars.remove(at:1);
print(cars);

TypeScript

const cars:string[] =
  ['Honda', 'Mazda', 'Toyota'];

// creates new array to newlist from index 1
const newList:string[] = cars.slice(1);
console.log(newList);

// cuts original list at index 1 to returnVal
const returnVal:string[] = cars.splice(1);
console.log(returnVal);
console.log(cars);

// add Ford to end of array
cars.push('Ford');
console.log(cars);

// removes last element Ford from array
cars.pop();
console.log(cars);

// adds Kia to beginning of array
cars.unshift('Kia');
console.log(cars);

// removes first element of array Kia
cars.shift();
console.log(cars);

// sorts array in alphabetical order
cars.sort();
console.log(cars);

Copyright 2025. All Rights Reserved. IronCodeMan.