How to put .ts variable into html method?

ionic-v1
1

Hi guys, how do i do this in the correct way
(selectOption)="selectOption($event,{{variable}})"
the variable is taken from .ts page

2

Just like how you do it in the usual way

(selectOption)="selectOption(event,variable)"

for example (click)="popup('abc','def') in HTML and
popup(input1, input2) { alert(input1 + input2); } will give alert with message abcdef