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Lambda Expressions
In Kotlin, a lambda expression is a function without a name. It’s used to define a code block that can be passed as an argument to a function or stored in a variable.
Defining a Lambda Expression
To define a lambda expression, you enclose a block of code in curly braces: {}. Then, you can assign the code block to a variable, such as the following:
val myFirstLambda = { println("This is my first lambda") }
fun main() {
myFirstLambda()
}
This is my first lambda
Lambda Expressions With Arguments
A lambda expression can take arguments and return a value. The syntax of a lambda expression taking two arguments of type Int looks like this:
val myLambda = { num1: Int, num2: Int ->
val sum = num1 + num2
// The value stored in sum is the value that will be returned when the `myLambda` lambda expression is executed since it's the last statement in the lambda.
sum
}
Type Inference
Kotlin’s type inference enables the compiler to evaluate the type of a lambda, such as in the myLambda expression:
val myLambda = { num1: Int, num2: Int ->
val sum = num1 + num2
sum
}
val stringLambda: (String) -> Int = { name: String ->
name.length
}
