Kotlin Programming Cookbook

Creating a chain of multiple lets in Kotlin

let is a pretty useful function provided by Kotlin's Standard.kt library. It is basically a scoping function that allows you declare the variable in its scope. Let's take a look at the given code:

someVariable.let{    // someVariable is present as "it"}

However, the best thing is that it can be used to avoid null checks. Earlier, you might have used the following:

if(someVariable!=null){    // do something }

While the preceding code is good, it's not very suited for mutating properties. The alternative is to use ?.let (someVariable.?let{}), which ensures that the code block runs when the variable is not null. However, what if we have multiple if-not-null chains? Let's see how to deal with those cases ...