I need to read and write data to/from a text file, but I haven't been able to figure out how. I found this sample code in the Swift's iBook, but I still don't know how to write or read data. import...
swift - Read and write a String from text file - Stack Overflow
Swift needs a convention for saying what the name of a function is, including not only the function name itself (before the parentheses) but also the external names of the parameters.
TL;DR Swift 5.9 $0, $1, $2 are Closure 's first, second and third Shorthand Argument Names or, in other words, implicit parameter names, if you like. The shorthand argument names are automatically provided by Swift. As you know, a closure is a self-contained block of functionality (a function/method without name) that can be passed around and used in your code. Closures have different names in ...
What does $0 and $1 mean in Swift Closures? - Stack Overflow
Use LOOKUP, one of the lookup and reference functions, when you need to look in a single row or column and find a value from the same position in a second row or column. For example, let's say you know the part number for an auto part, but you don't know the price.
Use the VLOOKUP function to look up a value in a table. The value you want to look up. The value you want to look up must be in the first column of the range of cells you specify in the table_array argument. Lookup_value can be a value or a reference to a cell.