How do I know which is the default measure system (imperial or metric) on iOS?

Question

How do I know which is the default measure system (imperial or metric) on iOS ?

How do I get this preference from the device settings, so I know what to display in m

Answer 1

@DarkDust answer for swift3

//User region setting return
let locale = Locale.current //NSLocale.current

//Returns true if the locale uses the metric system 
let isMetric = locale.usesMetricSystem