The important announcement by Google in 2017 for Android Developers is that kotlin is now an official language for Android App Development. For more on introduction and basic you can visit previous blog "Getting Started with Kotlin for Android App Development - An Introduction and Basics".

Coming to the topic, today in this tutorial, I will guide you about how we can navigate/switch and sending data between two activities. So, being an android developer you must have sent data between two activities but in kotlin the syntax's are different.

Let's see an example of two activities, in the first one, Data is sent to another activity and in next one Data is received:

Activity 1: Send data to another activity

package com.multipleactivities.android.activity

import android.content.Intent
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Button
import android.widget.EditText
import com.multipleactivities.android.R
import com.multipleactivities.android.constants.AppConstants

class FirstActivity : AppCompatActivity() {
    private var btnNavigate: Button? = null
    private var etWriteText: EditText? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_first)

        // initializing button
        initView()

        // button click
        define()
    }

    private fun initView() {
        btnNavigate = findViewById(R.id.btn_navigate) as Button
        etWriteText = findViewById(R.id.et_write_text) as EditText
    }

    private fun define() {

        btnNavigate!!.setOnClickListener {
            val intent = Intent(this@FirstActivity, SecondActivity::class.java)
            intent.putExtra(AppConstants.VALUE, etWriteText!!.text.toString())
            startActivity(intent)
        }
    }
}

In above code, you can see the kotlin syntax, we are sending user input to the another activity through intent.

Activity 2: Receiving Data

package com.multipleactivities.android.activity

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.TextView
import com.multipleactivities.android.R
import com.multipleactivities.android.constants.AppConstants

class SecondActivity : AppCompatActivity() {
    private var tvReceivedText: TextView? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_second)

        // initializing views
        initView()

        // receiving intent values
        receivingValue()
    }

    private fun receivingValue() {
        val intent = intent
        val value = intent.getStringExtra(AppConstants.VALUE)
        tvReceivedText!!.text = value
    }

    private fun initView() {
        tvReceivedText = findViewById(R.id.tv_received_text) as TextView
    }
}

In above code, you can see we getting the data using get intent and displaying it in textView.