Using Expression syntax

The syntax for the Expression is {!expression}. The Expression syntax can be used inside the Component Markup. Let's take a look at the following table to see the syntax for Expressions in different scenarios:

Expression Example	Syntax	Example Code
Expression to reference a value from an attribute	{!v.attributeName}	<aura:component> <aura:attribute name="searchString" type="String" default="lighnting components"/> <p>{!v.searchString}</p> </aura:component>
Expression for calling client-side controller actions	{!c.handleClick}	<Lightning:button label="Framework Button" onclick="{!c.handleClick}"/> The client-side JavaScript controller will be as following ({ handleClick : function(component, event) { } })
Expression operator	The operators...