use variable's value in if condition in jvascript

I have dynamic condition for if, how can I check it by using as this:-

var searchQuery = '(data.id == "1") && (data.first == "et")';

if(searchQuery === true)
    alert('yes');

this is only checking that variable is empty or not. but I need to check variable's value as statement and check it by if condition.

variable value is not static , even in value more than 2 arguments may exist. how to resolve this?