How to Each Active The Button By Onclick

ionic-v1
#1

I Have A Group Of buttons

 <button block outline ion-button> Button1 </button>
 <button block outline ion-button> Button2 </button>
 <button block outline ion-button> Button3 </button>
 <button block outline ion-button> Button4 </button>

How To Set Active Class(change background color) For Each Button.
if i click first button, button1 will active other buttons remains unchange

if i click Second button, button2 will active other buttons remains unchange

i want this functionality for all buttons,

Can Anyone Help