You need to create your own log file to record events in your application in your own way. Here is the most typical way to create a text file and save it on the disk of an iOS device like iPhone, iPad, iPod.
Double-precision, Floating-point numbers are numbers that have fractional parts (usually expressed with a decimal point). You should use a floating-point type in Swift programs whenever you need a number with a decimal, such as 24.02 or 3.25.
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