Jslint uses '||' operator instead of conditional operator

Question

I have jslint complaining about using the || for the code below

 query = ['browser' + (ieVersion ? ieVersion : 'UNKNOWN')] 

I tried using the || operator but the result is a wrong result

 query = ['browser' + ieVersion || 'UNKNOWN'] // => ['browserundefined'] 

Answer 1

Operator priority is incorrect, try the following:

 query = ['browser' + (ieVersion || 'UNKNOWN')] 

without additional brackets, the + operator is stronger, and the JavaScript engine evaluates it as:

 query = [('browser' + ieVersion) || 'UNKNOWN'] 

Note that 'browser' + ieVersion never false, so you will never see 'UNKNOWN' .

Answer 2

parentheses?

 query = ['browser' + (ieVersion || 'UNKNOWN')] 

Answer 3

You need to enclose the expression in parentheses:

 query = ['browser' + (ieVersion || 'UNKNOWN')]