INTRODUCTION TO ARRAY IN C LANGUAGE

INTRODUCTION TO ARRAY

• ADVANTAGE AND DISADVANTAGE
• DECLARATION OF ARRAY
• INITIALIZATION OF ARRAY
• 2-D ARRAY/INITIALIZATION
• PASSING ARRAY TO A FUNCTION 

A collection of identically typed data pieces kept in adjacent memory locations is called an array. Arrays are derived data types in C that are used to store primitive data types like int, char, double, float, etc. In addition, it may store a variety of derived data types, including pointers and structures. The simplest data structure is an array since each data component may be accessed at random by using its index number.

The C array comes in handy when you need to hold related elements. For instance, we don't need to construct separate variables for the marks in each topic if we need to keep a student's marks across six subjects. Alternatively, we can create an array that can store the marks for every subject at consecutive memory locations.

We can easily access the elements by utilizing the array. To access the items of the array, a few lines of code are all that are needed.

Array has some properties also let’s understand them

·       Each entry in the array, for instance, int = 4 bytes, has the same size and data type.

·       Array elements are stored in memory locations, with the first member being stored in the smallest position.

·       Since we can find the addresses of array items using a specified base address and data element size, you can use the array items at random.

 Advantage

1. Code Optimization: Use less code to access data more effectively.

2. A for loop may be used to rapidly and easily obtain array elements, which makes traversal a joy.

3. Simple sorting: A few lines of code are all that are needed to sort the elements in an array.

4. We can randomly access any element in an array.

Disadvantage

Fixed-size: Whatever size we specify while defining the table, we cannot exceed the limit. So it doesn't grow dynamically like LinkedList, which we'll learn about later.

 Declaration of array in c

we can declare the array like

Initialization of array

The basic method to initialize or identify the element is indexing. We can initialize each index to a particular element.

Suppose:

As we had seen above marks are the name of the array and the size of the array is 5 then:

Marks0 = 70; (initializing point)

Marks1 = 60;

Marks2 = 80;

Marks3 = 55;

Marks4 = 40;

70

60

80

55

40

 

Marks0

Marks1

Marks2

Marks3

Marks4

 

Let us understand this by a program

#include<stdio.h>  

int main(){   

Array declaration with initialization

 

Additionally, we may set the array's size at declaration time. Let's see how

int marks [5]={20,40,60,80,30}

In these circumstances, we can also initialize the value straight away without specifying the array's size.

int marks []={20,40,60,80,30}

Let us understand this a C program 

 

 

Let us understand some basic simple programs in C having arrays

 

We are now doing sorting of an array having bubble sort method to sort the array in ascending order

 

Try to have this program and comment your output.

Now we will try to print the largest as well as second largest element in the array

 

Try to have this program and comment on your output.

 

2-D (two dimensional) Array

 

A two-dimensional array can be defined as a collection of arrays. A matrix is really just a collection of rows and columns, and that is how a 2D table is organized. To create a data structure that is akin to a relational database, 2D tables are created. It makes managing enormous volumes of data at once easier and can be supplied to other activities as needed.

 

Let’s understand the syntax first

Data_type array_name[rows][columns]

Example

Int marks[2][4];

Here int shows the data type

Marks shows the name of the array

2 show the number of rows

4 shows the number of columns

 

Initialization of 2-D Array

 

When declaring and initializing a 1D array simultaneously, sizing is unnecessary. On the other hand, 2D arrays will not be able to use this. The second dimension of the array needs to be specified. An illustration of declaring and defining a two-dimensional array is provided here:

 

Let us understand this by an example

Int arr[4][3]={{1,2,3},{4,5,6},{7,8,9},{6,4,5}};

 

Let us understand this by a program

 

through

let us try to store elements in a matrix and print it

 Return an array in C

 

let us understand how to pass an array in a function

 The getarray() function is used in the preceding code snippet with an array of recently generated elements, arr[]. Basically, the getarray() method prints each element of the array arr[].

 Output

Elements of an array are 45 67 78 90 

Passing an array to a function

Let us understand the program

In the code above, we passed an array as a pointer to the function. The printarray() function prints the elements of an array.

Output

Elements of an array are A, B, C, D, E

 Returning pointer pointing to the array

  

In the program above, the function getarray() returns the variable arr.

Although a local variable is assigned a value, the memory space was illegally allocated by the stack function. All variables are removed from the stack when main() is called again. Given that this software replaces a deleted region in memory, it is safe to say that it creates a segmentation fault.

Array outside function (segmentation fault )

There are three ways of returning arrays to a function

• Using dynamically allocated array
• Using a static array
• Using structure

Let us figure out all three by a C program 

Returning array by passing an array which is to be returned as a parameter to the function.

Using static variable

Using Structure

Because structures are user-defined data types, they can include collections of different kinds of objects. The next stage is to build code that, when it runs, will produce an array using structure.