Question

a+ = a - - + ++ a + 2 * a ; if a=8, find the value of a.

Answer 1

$\textsf{\large{\underline{Answer}:}}$

• The final value of a after evaluating the given expression is 40.

$\textsf{\large{\underline{Solution}:}}$

Given:

> a = 8

On evaluating the given expression:

> a += a-- + ++a + 2 * a

> a = a + a-- + ++a + 2 * a

> a = 8 + a-- + ++a + 2 * a

> a = 8 + 8 + ++a + 2 * a    [a remains 8, post-increment]

> a = 16 + ++a + 2 * a   [a becomes 7]

> a = 16 + 8 + 2 * a  [a becomes 8, pre-increment]

> a = 24 + 2 * 8

> a = 24 + 16

> a = 40  (Answer)

$\texttt{\textsf{\large{\underline{Learn More}:}}}$

There are two types of increment/decrement operations.

1. Post increment/decrement.
2. Pre increment/decrement.

Post Increment/Decrement: Here, operation takes place first and then the value is incremented/decremented.

Example:

> int a = 2;

> int b = a++;

> b = 2

Now, a = 3.

Pre Increment/Decrement: Here, value is first increment/decrement and then the operation is carried out.

Example:

> int a = 2;

> int b = ++a;

> b = 3

Also, a = 3