Coding 101 21: Perl: Getting Started

Hosts: Fr. Robert Ballecer, SJ and Shannon Morse Guest: Patrick Delahanty Ivory Tower Control Structures * The structure of Perl is more like C# than Python -- While Python uses whitespace to delineate lines of code, Perl uses ";" a semicolon -- Also like C#, Perl uses "{}" Curly brackets to create BLOCKS of code Variables * Much like Python, Perl doesn't require you to declare variables seperately from expressions. * You can declare variable WITHIN the expression. Perl offers three types of variables: Scalars, Arays and Associative Arrays * We're going to show you the first two: Scalars and Arrays Printing in Perl * Printing in Perl works much in the same way as printing in Python * You can print numbers, strings, variables, and combinations thereof. Scalars * These are either numbers or strings * Perl doesn't require you to mark a variable as either a number or a string... it all looks the same to Perl * Perl also doesn't require you to differerentiate between integers and real numbers Usage of Scalars: * You declare a scalar variable by using "$" right befofe the name of the variable $Var1 = 28 Creates a variable named "Var1" containing the integer "4" $Var2 = "Coding 101" Crates a variable named "Var2" containing the string "Coding 101" $Var3 = 3.14 Creates a variable named "Var3" containing the decimal number "4.5" Arrays * An array is a ONE-DIMENSIONAL indexed list of Scalar variables Usage of Arrays * You declare an array by using "@" right before the name of the array * Individual scalar variables within the array can be accessed by pointing to their index with the SCALAR identifier @C101 = ("Padre", "Snubs", "Bryan") Creates an array named "C101" and fills it with the strings, "Padre", "Snubs" and "Bryan" @coding = @c101 Creates an array called, "coding" and fills it with the values from the array "c101" $C101[2] = "Cranky Hippo" Changes the value in the third item in the array "C101" from "Bryan" to "Cranky Hippo" Get in Touch With Us! * Subscribe and get Coding 101 automatically at TWiT.tv! * Follow PadreSJ and Snubs on Twitter. * Watch the show live and join the chatroom every Thursday at 1:30pm PST. * Email us at Padre@twit.tv and Shannon@twit.tv. * Join our Google+ Community! Bandwidth for Coding 101 is provided by Cachefly. Running time: 42:03

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