# Kotlin Variables

A variable refers to a memory location that stores some data.   
You can declare variables in Kotlin using the **val** and **var** keywords.

**val:**  
A variable declared with the val keyword is read-only (immutable). It cannot be reassigned after it is initialized.

```kotlin
val name = "Kotlin"
name = "Language" //Error: val can not be reassigned
```

It is similar to the *final* variable in Java.

**var:**  
Variable declared using var keyword is mutable. It can be reassigned after it is initialized.

```kotlin
val name = "Kotlin"
name = "Language" //No error. It works
```

It is similar to regular variable in Java.

**Type inference:**  
In Kotlin, it is not mandatory to explicitly specify the type of variable that you declare. The Kotlin compiler will automatically infer the type of the variable from the initialized section.

```kotlin
val name = "Kotlin" // type infered as "String"
val value = 100 //type infered as "Int"
```

You can also explicitly define the type of the variable.

```kotlin
val name: String = "Kotlin"
val value: Int = 100
```

Type of the variable declaration mandatory if you dont initialize the variable.

```kotlin
val name // Error: variable must either have a Type annotation or be initialized
name = "Kotlin"
```

You can also declare something like this.

```kotlin
val name: String //works
name = "Kotlin"
```

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