In the given reaction,

The number of $$\pi$$ electrons present in the product 'P' is ______.

Cyclohexanone contains $$\alpha$$-hydrogens. In the presence of $$OH^-$$ followed by heating, it undergoes self-aldol condensation.

In the first step, hydroxide ion removes an $$\alpha$$-hydrogen from cyclohexanone to form an enolate ion.

The enolate ion then attacks the carbonyl carbon of another cyclohexanone molecule, forming a new carbon-carbon bond and producing a $$\beta$$-hydroxy ketone (aldol).

On heating, the $$\beta$$-hydroxy ketone undergoes dehydration to form an $$\alpha,\beta$$-unsaturated ketone.

The major product $$P$$ is 2-(cyclohexylidene)cyclohexan-1-one.

The product contains:

1. One carbonyl double bond, $$C=O$$

   $$1\ \pi\text{-bond} = 2\ \pi\text{-electrons}$$

2. One carbon-carbon double bond, $$C=C$$

   $$1\ \pi\text{-bond} = 2\ \pi\text{-electrons}$$

Therefore, the total number of $$\pi$$ electrons in product $$P$$ is

$$2+2=4$$

Hence, the number of $$\pi$$ electrons present in the major product is

$$\boxed{4}$$