title: kotlin coroutine - what is default scope?
body: <p>How does coroutines default scope work if i do not specify anything. lets take a look at this example:</p>
  
  <pre><code>class MyAppCompatActivity:AppCompatActivity{
  fun getContact() {
          GlobalScope.launch {
              val contact = contacts.getContact() // suspended function
              withContext(Dispatchers.Default) {
                 phoneContact.value = contact }
          }
      }
  }
  </code></pre>
  
  <p>which simply updates the UI when a contact is retrieved.  this is added to the global scope of so the coroutine life span can be that of the entire application.</p>
  
  <p>but lets do the same thing again without a globalScope:</p>
  
  <pre><code>class MyAppCompatActivity:AppCompatActivity{
  fun getContact() {
          launch {
              val contact = contacts.getContact() // suspended function
              withContext(Dispatchers.Default) {
                 phoneContact.value = contact }
          }
      }
  }
  </code></pre>
  
  <p>what is the lifespan of getContact now that i have removed the globalScope ? is it tied to the MyAppCompatActivity scope ? </p>