how to add layers in master page and move contents to it in indesign using javascript

[Karthik SG]

    app.documents[0].layers.add ({name: 'A', layerColor: UIColors.RED});
    app.documents[0].layers.item('Layer 1').name = 'B';
    var currentItem = app.activeDocument.pageItems.item(0);
    currentItem.move(app.documents[0].layers.item('A'));
//app.documents[0].masterSpreads[0].layers.add(); //this property is not available

How to add new layer in masterSpreads[0] and move masterPage contents to that layer. I did it in pages but unable to do it with masterpage. If there is anyway help me out!

[Peter Kahrel]

You don't really move a page item to a layer, you simply change the item's layer:

currentItem.itemLayer = app.documents[0].layers.item('A');

[Karthik SG]

HI @Peter Kahrel,

sorry I was mistaken already, actually i am trying to select current layer items and move it to newly created layer via script!

I created new layer but now I don't know how to select the current layer items and move it to new layer. If you have idea about it please help me with this point!

[Robert Tkaczyk]

Layers are "global" - same layer is present on Pages and MasterSpreads. 

So you are not adding Layers to Pages - but to the Document.

[Karthik SG]

Oh I don't have much knowledge about layers before! Thanks for Information @Robert Tkaczyk 

[Peter Kahrel · Accepted solution]

Select an item on the source layer, then run this script:

app.selection[0].itemLayer.pageItems.everyItem().itemLayer = 
  app.documents[0].layers.item('A');

It moves all page items on that layer to layer A.

[Karthik SG]

Thank you so much @Peter Kahrel , it is working fine now