let keyword in kotlin code example

Example 1: let keyword in kotlin

let takes the object it is invoked upon as the parameter and returns the result of the lambda expression.

fun main(args: Array<String>) {
    var str = "Hello World"
    str.let { println("$it!!") }
    println(str)

}
The 'it' keyword contains the copy of the property inside let. In this case "Hello world"
//This prints:
//Hello World!!
//Hello World

Example 2: let keyword in kotlin

let can be used to check null expressions. 

fun main(args: Array<String>) {
	var name : String? = "Kotlin let null check"
	name?.let { println(it) } //prints Kotlin let null check
	name = null
	name?.let { println(it) } //nothing happens
}

//The code inside is executed only when the property is not null.