How can we pass Parameters from component to Jscontroller in Salesforce Lightning?

Hi suraj,

Somthing like this:
<aura:iteration items="{!v.newCases}" var="case">
<button type="button" onclick="{!c.showCaseDeleteModal(case.Id)}">Delete</button>
</aura:iteration>

You can further refer to this article : https://developer.salesforce.com/blogs/developer-relations/2015/03/lightning-components.html

Thanks.