I want to add a variable like this. Day value is an Integer
var day = component.find('days').get('v.value');
var date1 = component.find('HDate'+day+'__c').get('v.value');
But it returns an error at get(). How can I add a variable inside a find markup
Thanks in advance :)
It's unlikely that this is correct:
var date1 = component.find('HDate'+day+'__c').get('v.value');
because it appears to imply that your component is either iterating and generating a list of elements with aura:ids like HDate1__c and HDate2__c, or that the aura:id of this component is dynamically derived from another component attribute.
Since Aura Ids cannot be dynamic in Lightning component markup and you haven't shown us any indication you're creating components dynamically in JavaScript, I think it's likely that you are mistaken about what the actual aura:id values of the elements in your component are, and that component.find() is not returning you a component.
More broadly, component.find() can return undefined, a single component, or n array of components, and you need to be prepared to handle those return values based on your component markup.
