DEFINITION:

An array is a varible which store multiple values of homogenous (same) datatype. It is a type of variable
which stores more than 1 value. Each value is stored inside an index number. If you want to access a single
value from the array we use index number to access each of the single value stored inside an array.

In the above example, We have created an ARRAY which can store 5 values inside it.

There are 3 types of Array statements in C:

In this chapter we are going to learn about only 2 types: 1-D & 2-D Array.

SYNTAX: TO CREATE AN ARRAY

datatype arrayName[arraysize] = {value1,value2,....valueN};
    

EXAMPLE:

int subject_marks[6] = {35,45,49,40,38,32};
    

NOTE:

Each value inside the array is stored inside an index number. Index value starts from 0 and ends with n-1.
Where n is size. Meaning, 1st value is stored inside index number 0 and last nth value is stored inside n-1 index number.

EXAMPLE:

//Write a program to take 5 subject marks from the user & display the subject marks on the screen using 1-D Array.

#include

int main()
{
	int subject_marks[5],i;

	printf("Enter 5 subject marks according to this sequence:\n1. English\n2. Hindi\n3. Marathi\n4. Maths\n5. Science\n\n-> ");

	for(int i=0;i<5;i++)
	{
		scanf("%d",&subject_marks[i]);
	}
	
	//Displaying Marks obtained in Each Subject
	printf("\n\nDisplaying marks....\nAccording to the sequence given above.\n\n");

	for(i=0;i<5;i++)
	{
		printf("%d\n",subject_marks[i]);
	}
	return 0;
}
    

In the above program, We used 1-D Array to store 5 subject values and displayed on the screen.

OUTPUT:

Enter 5 subject marks according to this sequence:
1. English
2. Hindi
3. Marathi
4. Maths
5. Science

-> 38
34
48
44
39
49


Displaying marks....
According to the sequence given above.

38
34
48
44
39
49
    

DEFINTIION:

2-D Array stands for 2 Dimensional Array. It consists of 2 sizes:

1. size1 -> row size
2. size2 -> column size

SYNTAX: TO CREATE 2-D ARRAY

There are many ways to create an 2-D Array but we will use only 1 way to create the variable with value.

datatype arrayName[size1][size2] = {value1,value2,value3,.......}; //Where size1 = rowsize AND size2 = columnsize
    

For example, we have given rowsize & columnsize as 3 & 4 so we can add upto 12 values in the 2-D Array.

EXAMPLE:

//Write a program to take 4 values from the user and then display the values in the form of 2 x 2 Matrix

#include

int main()
{
	int i,j,numbers[2][2];

	printf("Enter the numbers:\n");
	for(i=0;i<2;i++)
	{
		for(j=0;j<2;j++)
		{	
			scanf("%d",&numbers[i][j]);
		}
	}

	
	printf("\n\nDisplaying the values in the form of 2 x 2 Matrix\n\n");
	for(i=0;i<2;i++)
	{
		for(j=0;j<2;j++)
		{
			printf("%d\t",numbers[i][j]);
		}
		printf("\n");
	}

	return 0;
}
    

In the above program, We have used 2-D Array to store the values and display the value in the form of 2 x 2 Matrix.

OUTPUT:

Enter the numbers: 
2
3
4
5


Displaying the values in the form of 2 x 2 Matrix


2	3
4	5
    

NOTE:

To understand about the 2-D array you must be familiar with the Nested for loop concept as well as the Conditional statements in C.

DEFINITION:

In this topic, we learn about how to pass an array as an argument to a function having array as an parameter.

EXAMPLE:

//Write a program to pass subject marks to displayMarks() 

#include stdio.h

void displayMarks(int marks[]);

int main()
{
	int subject_marks[5],i;
	
	printf("Enter 5 subject marks: \n");
	
	for(i=0;i<5;i++)
	{
		scanf("%d",&subject_marks[i]);
	}

	displayMarks(subject_marks);	

	return 0;
}

void displayMarks(int marks[])
{
	int i;
	printf("\nDisplaying marks....\n\n");
	for(i=0;i<5;i++)
	{
		printf("Subject %d: %d\n",i+1,marks[i]);
	}
}
    

In the above program, We have passed subject_marks array as an argument to the parameter of the displayMarks().

OUTPUT:

Enter 5 subject marks:
35
40
45
48
32

Displaying marks....

Subject 1: 35
Subject 2: 40
Subject 3: 45
Subject 4: 48
Subject 5: 32
    

Video Explanation

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Practice Task

Write a program to calculate sum of n natural numbers

Challenge

Try to create an interesting mini project with Arrays as we can store multiple value inside a variable.