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# Difference between Array and String

Last Updated on April 12, 2023 by Prepbytes

Arrays and strings are two essential data structures in computer programming that store collections of data. Although they may seem similar at first glance, But they are a lot of differences between array and string. Arrays and strings share some similarities, they are distinct data structures with different characteristics and use cases. Understanding these differences is important for choosing the appropriate data structure for a given programming problem.

## What is an Array?

An array is a data structure that stores a collection of similar data types in contiguous memory locations. In other words, it’s a collection of elements of the same type that are stored in a continuous block of memory. Arrays are used to store and manipulate large sets of data and are commonly used in programming languages like Java, C, C++, and Python.

Arrays can be one-dimensional, two-dimensional, or multi-dimensional, depending on the number of indices they have. Each element in an array is accessed by its index, which is an integer value representing its position in the array. Arrays are mutable, which means you can modify their values at any time.

Code Implementation

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

int main() {
// Declare an array of integers
int numbers[5] = {2, 4, 6, 8, 10};

// Print the entire array
cout << "The array is: ";
for(int i = 0; i < 5; i++) {
cout << numbers[i] << " ";
}
cout << endl;

// Access the third element (index 2) and print it
cout << "The third element is: " << numbers[2] << endl;

// Change the value of the fourth element (index 3)
numbers[3] = 12;

// Print the modified array
cout << "The modified array is: ";
for(int i = 0; i < 5; i++) {
cout << numbers[i] << " ";
}
cout << endl;

// Calculate the sum of all elements in the array
int total = 0;
for(int i = 0; i < 5; i++) {
total += numbers[i];
}
cout << "The sum of all elements is: " << total << endl;

return 0;
}
```

Output

``````The array is: 2 4 6 8 10
The third element is: 6
The modified array is: 2 4 6 12 10
The sum of all elements is: 34``````

Explanation
In this example, we declare an array of integers named numbers with 5 elements. Here’s an explanation of the code:
int numbers[5] = {2, 4, 6, 8, 10}; is how you create an array of integers in C++. We declare an array with the name numbers and 5 elements. The initial values of the elements are {2, 4, 6, 8, 10}. The for loops are used to iterate through the array and perform the desired operations. Cout is used to output the results to the console.

In this example, we printed the entire array, accessed and printed the third element (which is 6), changed the value of the fourth element to 12, printed the modified array, and calculated the sum of all elements in the array (which is 34).

## What is a String?

A string is a sequence of characters that represent a text value. It’s a data type used to store a collection of characters or symbols, such as letters, digits, and punctuation marks. Strings are often used in programming languages for input and output operations, such as reading data from a file or displaying output on a screen.

Strings are immutable, which means that once they are created, their values cannot be modified. You can concatenate two or more strings to create a new string, but you cannot change the original strings.

Code Implementation

```#include <iostream>
#include <string>
using namespace std;

int main() {
// Declare a string variable
string greeting = "Hello, world!";

// Print the string
cout << greeting << endl;

// Get the length of the string
int length = greeting.length();
cout << "The length of the string is: " << length << endl;

// Access the third character (index 2) and print it
char thirdChar = greeting[2];
cout << "The third character is: " << thirdChar << endl;

// Modify the string
greeting[7] = 'W';
cout << "The modified string is: " << greeting << endl;

// Concatenate two strings
string name = "in prepbytes ";
string message = "Welcome, " + name + "!";
cout << message << endl;

return 0;
}
```

Output

``````Hello, world!
The length of the string is: 13
The third character is: l
The modified string is: Hello, World!
Welcome, in prepbytes !``````

Explanation
In this example, we declare a string variable named greeting and assign it the value "Hello, world!". Here’s an explanation of the code:
string greeting = "Hello, world!"; is how you create a string variable in C++. We declare a string with the name greeting and the value "Hello, world!".
cout is used to output the results to the console. A string is a C++ library that allows you to work with strings. In this example, we printed the string, got the length of the string (which is 13), accessed and printed the third character (which is l), modified the string by changing the eighth character to ‘W’, concatenated two strings ("Welcome, " and "in prepbytes "), and printed the concatenated string.

## Difference between Array and String

Here we have the difference between array and string

Array                     String
An array is a collection of similar data types such as integers, character A string is a sequence of characters
Array are mutable, which means you can modify their values at any time A string is immutable  which means you cannot modify its values after they are created
The length of an array is fixed, we  need to specify the number of elements it will contain when we create it The length of the string is not fixed, it can grow or shrink dynamically as you add or remove characters
Memory allocation in the array, Stores values in contiguous memory locations It stores characters in separate memory locations
An array can hold any of the data types A string can hold only a char data type

Conclusion
Now we can conclude that An array is a linear data structure and a collection of elements with the same data type. These are particularly strong in a contiguous memory zone. Arrays are used to group together data of the same type.
A string is a sequence of characters, or it can be defined as a collection of objects of the char data type. Arrays and strings are both essential data structures in computer programming that serve different purposes. Arrays are used to store and manipulate large sets of data, while strings are used to represent text values. Understanding the differences between these two data structures is essential for choosing the right one for your programming needs.

Here we have FAQs on the difference between array and string

Q1. Can arrays and strings be used interchangeably?
Ans. No, arrays and strings cannot be used interchangeably because they have different data types and properties. While arrays are used to store collections of data of a particular data type, strings are used to store text values as a sequence of characters.

Q2. Can strings be mutable?
Ans. No, strings are immutable, which means that their values cannot be changed after they are created. However, you can create a new string by concatenating two or more existing strings.

Q3. Are arrays more efficient than strings?
Ans. The efficiency of arrays and strings depends on the specific use case and the programming language being used. Generally, accessing elements in an array is more efficient than accessing characters in a string because arrays store their values in contiguous memory locations. However, strings have built-in functions for common operations, which can make them more efficient for certain tasks.

Q4. Can arrays and strings be passed as arguments to functions?
Ans. Yes, both arrays and strings can be passed as arguments to functions. When passing an array to a function, you can pass it by reference or by value. When passing a string to a function, it is typically passed as a pointer to the first character in the string.

Q5. What are some common use cases for arrays and strings?
Ans. Arrays are commonly used for tasks such as sorting and searching data, implementing other data structures such as stacks and queues, and storing large sets of data. Strings, on the other hand, are commonly used for tasks such as parsing text files, processing user input, and formatting output in applications.