Kotlin Android print to console

Question

I need to print some str to console (Android Studio) using Kotlin. I've tried the:

Log.v()  Log.d()  Log.i()  Log.w()  Log.e()  

methods. But it seems to work only on Java. What should I use to print using Kotlin? Thanks

Answer 1

There are a couple of ways.

You can use Log.d("TAG", "message"); for example but first you need to import Log.

import android.util.Log  {...}  Log.d("TAG", "message")  {...} 

Source: https://developer.android.com/reference/android/util/Log.html

You can also use kotlin's print and println function.

Example:

{...}  print("message")  println("other message")  {...} 

Source: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.io/

Answer 2

I've written some extension functions that make use of reified type parameters in order to avoid dealing with declaring log tags in all project's classes. The basic idea is shown by the following snippet:

inline fun <reified T> T.logi(message: String) = Log.i(T::class.java.simpleName, message) 

Basically, you can log something to the logcat with the following invocation (W/O external dependencies):

logi("My log message") 

You can find a gist here. The functions declared in the gist are a little more elaborated given that they allow:

• Lazy evaluation of the string to be logged out (if for example the string needs to be generated in some way)
• Logging only when in debug mode by default
• Use a given class name when you need to log from within an anonymous class that has no name