Question

Assume that an array of integers named a that contains exactly five elements has been declared and initialized. Write a single statement that assigns a new value to the first element of the array. This new value should be equal to twice the value stored in the last element of the array.

Answer 1

In any programming language, the assignment statement is written as shown.

a[0] = 2*a[4];

Step-by-step explanation:

This scenario is explained in c++ language.

An array is declared as follows.

Datatype array_name[length];

The variable length denotes the number of elements in the array. It is also an integer variable.

An element in the array is written as arr[k], where value of k ranges from 0 to ( length-1 ).

The first element is written as array_name[0], second element is written as array_name[1], and so on.

The elements in the array are initialized as shown.

array_name[0] = value1;

array_name[1] = value2;

For the given scenario, an integer array a is declared.

The variable length will be initialized to 5, which means the array a has exactly 5 elements.

int length = 5;

int a[length];

The elements of array a are initialized as shown.

a[0] = 1;

a[1] = 2;

a[2] = 3;

a[3] = 4;

a[4] = 5;

As per the given scenario, the first element of the array, a[0], needs to be assigned a new value. This new value is twice the value of the last element of the array, a[4].

The assignment statement is written as shown.

a[0] = ( 2 * a[4]) ;

The above statement assigns twice the value of the last element to the first element.

Thus, after the above statement is executed, the old value of a[0] which is 1 is over written.

Now, a[0] will hold new value which is

( 2 * a[4] )

= ( 2 * 5 )

= 10.

The value of the first element, a[0], is changed from 1 to 10.

The above can be programmed as shown.

#include <iostream>

using namespace std;

int main() {

int length = 5;

int a[length];

a[0] = 1;

a[1] = 2;

a[2] = 3;

a[3] = 4;

a[4] = 5;

a[0] = (2*a[4]) ;

return 0;

}