Aura if else condition in salesforce lightning

<aura:component implements="force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:hasRecordId,forceCommunity:availableForAllPageTypes" access="global" > <aura:attribute name="FirstName" type="String"/> <aura:attribute name="LastName" type="String"/> <aura:attribute name="mobile" type="Integer"/> <aura:attribute name="Email" type="String"/> <aura:attribute name="details" type="boolean" default="true" /> <aura:renderIf isTrue="{!v.details}"> <div align="center" style="width:300px;"> <lightning:input type="Text" label="FirstName" placeholder="Please enter FirstName" aura:id="FirstName" value="{!v.FirstName}" updateOn="keyup" /> ...