JAVA

start activity intent

Intent myIntent = new Intent(CurrentActivity.this, NextActivity.class);
myIntent.putExtra("key", value); //Optional parameters
CurrentActivity.this.startActivity(myIntent);

Intent Start Another Activity

    public void sendMessage(View view) {
        Intent intent = new Intent(this, DisplayMessageActivity.class);
        startActivity(intent);
    }
        /*DisplayMessageActivity is the name of the other activity*/

start activity intent

Intent myIntent = new Intent(CurrentActivity.this, NextActivity.class);
myIntent.putExtra("key", value); //Optional parameters
CurrentActivity.this.startActivity(myIntent);