How we can use a map in Salesforce Lightning Component?

Hi,

You can use a map in Salesforce Lightning Component like this :-

<aura:component implements="forceCommunity:availableForAllPageTypes" access="global" controller="MyClass">
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    <aura:attribute name="myMap" type="Map" />
</aura:component>

({
   doInit: function(component, event, helper) {      

       var action = component.get('c.getMap');
        
        action.setCallback(this,function(result){
            component.set('v.myMap',result.getReturnValue());
        });
        $A.enqueueAction(action);
     }
})

public with sharing class MyClass
{
      public static MAP<String,String> getMap()
      {
          Map<String,String> map = new Map<String,String>();
          map.put('key1','value1');
          map.put('key2','value2');
          return map;
      }
}

For more, you can take help from this URL.