C Program to insert an Element in an Array

In this article We are going to show you, How to insert an element in a predefined Array at user specified location using For Loop and While Loop. Before going into this article Please refer Arrays in C article to understand the concept of Array size, index position etc.

C Program to insert an Element in an Array using For Loop

This program allows the user to enter the array size, Elements of an Array, Location of a element and the value of an element. Using For Loop in C Programming we are going to insert the value in an Array at the user specified location.

CODE

#include <stdio.h>

int main()

{

int Array[10], Position, i, Number, Value;

printf("\nPlease Enter Number of elements in an array\n");

scanf("%d", &Number);

printf("\nPlease Enter %d elements of an Array \n", Number);

for (i = 0; i < Number; i++)

{

scanf("%d", &Array[i]);

}

printf("\nPlease Enter the location of a Element you want to insert\n");

scanf("%d", &Position);

printf("\nPlease Enter the value of an Array Emenent to insert\n");

scanf("%d", &Value);

for (i = Number - 1; i >= Position - 1; i--)

{

Array[i+1] = Array[i];

}

Array[Position-1] = Value;

printf("\n Final Array after Inserting an Elemnt is:\n");

for (i = 0; i <= Number; i++)

{

printf("%d\t", Array[i]);

}

return 0;

}

OUTPUT

ANALYSIS

In this Program, We declared One dimensional arrays with the size of 10 and we also declared i value to iterate the for loop, Position variable to hold the location of an inserting element and Value is the Element you wish to insert.

Below printf statement asks the User to enter the Array size (Number of elements in an Array. For instance 4 elements = a[3])

1	printf("\nPlease Enter Number of elements in an array\n");

Below scanf statement will assign the user entered values to Number variable.

1	scanf("%d", &Number);

Below for loop will helps to iterate each and every cell present in the Array[3] array. Condition inside the for loops (i < Number) will ensure the compiler, not to exceed the array size. Otherwise the array will overflow

scanf statement inside the for loop will store the user entered values in every individual array element such as a[0], a[1], a[2]

for (i = 0; i < Number; i++)

{

scanf("%d", &Array[i]);

}

Below printf statement asks the User to enter the location where you wish to insert the new element and scanf statement will assign the user entered value to the Position Variable

printf("\nPlease Enter the location of a Element you want to insert\n");

scanf("%d", &Position);

Below printf statement asks the User to enter the value you wish to insert the at the user defined location and scanf statement will assign the user entered element to the Value Variable

printf("\nPlease Enter the value of an Array Emenent to insert\n");

scanf("%d", &Value);

From the above screenshot you can observe that,

Array Size = 4 and Elements of an Array are {10, 20, 30, 40}. This means

Array[0] = 10

Array[1] = 20

Array[2] = 30

Array[3] = 40

Position of an Element = 2 and User Entered Value is 89

for (i = Number - 1; i >= Position - 1; i--)

{

Array[i+1] = Array[i];

}

First Iteration

i = Number–1 means i will be initializes to 3

i=3, position = 2

Condition inside the For loop (i >= Position – 1) is True because (3 is greater than 1)

Array[i+1] = Array[i];

Array[4] = Array[3]

Array[4] = 40

After the statements is executed i value will be decremented to 1 because we used Decrement Operator in For Loop.

Second Iteration

After decrementing, i value become 2. So,

i=2, position = 2

Condition inside the For loop (i >= Position – 1) is True because (2 is greater than 1)

Array[i+1] = Array[i];

Array[3] = Array[2]

Array[3] = 30

Third Iteration

After decrementing, i value become 1. So,

i=1, position = 2

Condition inside the For loop (i >= Position – 1) is True because (1 is Equal to 1)

Array[i+1] = Array[i];

Array[2] = Array[1]

Array[2] = 20

After decrementing, i value become 0. It means the condition inside the For loop will fails. So compiler will exit from the for loop.

Up to Now the final array will be: Array[4] = {10, 20, 20, 30, 40}

Now we have to insert the new element at the position 2. Below statement will do the trick for you

Array[Position-1] = Value;

Array[2-1] = 89;

Next for loop,

for (i = 0; i <= Number; i++)

{

printf("%d\t", Array[i]);

}

Will traverse all the elements in the Array as we explained above and, it will display the values inside the Array[i] array using the printf statements array.