Lightning - How to identify which button was clicked using event

How to identify which button was clicked using event

In order to find which button was clicked we can use event methods.
In the below example I used three button.

With below piece of code we can find which button was clicked. On click of a button a controller method will be called 
inside that methos we can use event methods to capture the information. 

var source = event.getSource(); // From which element/source event was fired ?
var id = evt.getLocalId(); // Id of the element from which event was fired
var name = evt.get("v.name"); // Name of the element from which event fired

By using this we can perform the operations. 
In this below example i used only one controller method to perform Addition, Multplication and Reset.

Component: 
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<aura:component >
    <aura:attribute name="aval" type="Integer"/>
    <aura:attribute name="bval" type="Integer"/>
    <aura:attribute name="cval" type="Integer"/>
	<lightning:card iconName="standard:account">
    	<aura:set attribute="title">
            Calculator<br/>
            Simple Calculator
        </aura:set>
        <aura:set attribute="actions">
        	<lightning:buttonGroup>
                <lightning:button label="Add" name="Addition" aura:id="add" onclick="{!c.generic}"/>
                <lightning:button label="Mul" name="Multiplication" aura:id="mul" onclick="{!c.generic}" />
                <lightning:button label="Reset" name="Reset" aura:id="reset" onclick="{!c.generic}" />
            </lightning:buttonGroup>
        </aura:set>
        <aura:set attribute="footer" >
            <lightning:badge label="All Rights Reserved"/> 
        </aura:set>
        <lightning:input label="Enter the Aval" type="number" value="{!v.aval}" required="true"/>
        <lightning:input label="Enter the Bval" type="number" value="{!v.bval}" required="true"/>
        <lightning:input label="Result" type="number" value="{!v.cval}"/>
    </lightning:card>
</aura:component>
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Controller: 
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({
	generic : function(component, event, helper) {
        
        var source = event.getSource();
        var aval = component.get("v.aval");
        var bval = component.get("v.bval");
        if(source.getLocalId()== 'add')
        {
            var result= parseInt(aval)+parseInt(bval);
            component.set("v.cval",result);
        }
        else if(source.getLocalId()== 'mul')
        {
        	var result= parseInt(aval)*parseInt(bval);
            component.set("v.cval",result);
        }
        else
        {
			component.set("v.aval",null);
			component.set("v.bval",null);
			component.set("v.cval",null);            
        }
		
	}
})
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