The below code shows how to use Ternary Operator in Salesforce Lightning Components:

Ternary_Operator.cmp

<aura:component >
    <aura:attribute name=”isError” type=”Boolean” description=”If Name is empty then true, else false”/>
    <aura:handler name=”init” value=”{!this}” action=”{!c.doInit}” />
    <div class=”init”> 
        <lightning:input label=”Enter your Name” aura_id=”FullName” class=”{!v.isError == true ? ‘error errorBorder’ : ‘correct correctBorder’}” onchange=”{!c.handleNameChange}” />
    </div>
</aura:component>

Ternary_Operator.js

({
    doInit: function(component) {
        component.set(“v.isError”,true);
    },
    handleNameChange : function(component){
        var name = component.find(“FullName”).get(“v.value”);
        if(name == null || name == ” || name == undefined){
            component.set(“v.isError”,true);
        }
        else{
            component.set(“v.isError”,false); 
        }
    },
})

Ternary_Operator.css

.THIS {}
.THIS .error{ background-color:#D25A5A;}
.THIS .correct{ background-color:#a3ea82;}
.THIS .errorBorder{ border-color: red; border-width: 10px; border-style: solid;}
.THIS .correctBorder{ border-color: green; border-width: 10px; border-style: solid; }
.THIS.init{ width:50%; position:relative; left:200px; top:100px; }

Ternary_OperatorApp.app

<aura:application extends=”force:slds”> <c:Ternary_Operator/></aura:application>

Happy Salesforce Coding!