# Kotlin Expression and Statement

In programming, expressions and statements are two fundamental concepts.

- An
**expression**is a combination of one or more values, operators, and/or function calls that returns a value. Expressions can be simple or complex, and they can include literals, variables, and other constructs.

For example, `x + y`

is an expression that adds the values of `x`

and `y`

and returns the result.

- A
**statement**is a single line or block of code that performs a specific task, such as assigning a value to a variable, calling a function, or looping through a collection of items. Statements can contain one or more expressions.

For example, the following is a statement that assigns the value of `10`

to the variable `x`

:

val x = 10

Here's another example of a statement that uses an expression:

fun main() { val x = 10 val y = 20 val z = x + y // expression println("The sum of $x and $y is $z") // statement }

In this program, the expression `x + y`

calculates the sum of `x`

and `y`

, and the statement `println("The sum of $x and $y is $z")`

prints a message to the console that includes the value of `x`

, `y`

, and `z`

.

In Kotlin, every statement is also an expression. This means that a statement can return a value, and that value can be used as part of a larger expression or statement. For example, the following program uses a conditional expression to calculate the absolute value of a number:

fun main() { val x = -10 val absX = if (x < 0) -x else x // conditional expression println("The absolute value of $x is $absX") // statement }

In this program, the conditional expression `if (x < 0) -x else x`

calculates the absolute value of `x`

, and the statement `println("The absolute value of $x is $absX")`

prints the result to the console. Note that the `if`

expression is a statement that returns a value, which is then assigned to the variable `absX`

.