title: Is there a way to push key value pairs in google earth engine in a loop that is using the map() function?
body: <p>I am doing a spatiotemporal analysis of LULC on google earth engine. 
  For this, I have imported Landsat 5 tier 1 TOA reflectance images and filtered them by my preference. Following this I was able to extract the id values of the features in the filtered image collection, I need to create a dictionary in order to be able to assign the unique names from ID extracted by slicing the ID's and assign a value(id itself) to each pair.</p>
  
  <p>The id obtained of images in an image collection is of the type: LANDSAT/LT05/C01/T1_TOA/LT05_148045_19890509 
  in this,
  key:19890509
  value:LT05_148045_19890509 </p>
  
  <p>both of which can be obtained from slicing the obtained ID</p>
  
  <p>I have filtered the image collection and tried to create a dictionary as follows but it creates an empty dictionary. </p>
  
  <pre><code>// Create a list of image objects.
  var imageList = Collection.toList(100);
  print('imageList', imageList);
  
  // Extract the ID of each image object.
  var dicty = ee.Dictionary({}); //def dict for names
  var id_list = imageList.map(function(item) {
      var list_nm = ee.Image(item).id();
      var lst_nm_slice = ee.Image(item).id().slice(-8,-1);
      dicty.lst_nm_slice = list_nm;
      return dicty;
  });//end of map function
  </code></pre>
  
  <p>I expect the output of dicty to be a dictionary of key-value pairs with each key value getting assigned dynamically in the aforementioned loop so that I can call the images by using the dictionary key value pairs.</p>