Basic DataTypes in Kotlin

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In Kotlin, each variable and data structure has a type. These kinds are crucial because they inform the compiler of the operations that can be performed on them. To put it another way, the characteristics of a variable or data structure are determined by its type.
Just like Java, we don’t need to declare a variable’s type during declaration. Kotlin infers the variable’s type, and this ability is called type inference. So, if we declare a variable like

val customers = 10   // it means the customer is assigned an integer value

Kotlin infers that customers can execute arithmetic operations and have a numerical data type. For example.

fun main() {
    var customers = 10

    // since it's a var so we can re-assign it
    customers = 100

    // example of arithmetic operations
    // 1. addition
    customers = customers + 10  // results to 110

    /**
     * instead of writing the whole expression we can shorten everything using
     * augmented assignment operators
     * +=, -=, *=, /=, %=
     */
    customers += 10    // this results to 120

    // 2. subtraction
    customers -= 30     // this results to 90

    // 3. multiply
    customers *= 5      // this results to 450

    // 4. division
    customers /= 4      // this results to 112 (which is close to 112.5)

    println(customers)

}

Why did we receive 112 instead of 112.5? The short explanation is that Kotlin makes decisions based on the initial value we set to a variable. It reads the type as a decimal value if we assign 10.5, the outcome is 112.5 rather than 112.

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The other types in Kotlin are:

Sourced from: https://kotlinlang.org/docs/home.html

With this basic information, we can start declaring variables and understand the types of declared variables.