See the table of contents for my other blog posts from the conference

@aalmiray

Java is 23 years old. Go is 9 years old

To run

• go run prog.go – compile to temp directory and run
• go build pro.go – explicitly compile
• ./prog

Syntax

• package name [no semicolons]
• import “target”
• fun main() {}
• fmt.Println(“Hello World”)
• fmt.Println(“one”, “two”)
• if a == b [no parens]
• func name(type int) int { return 0 }
• fun name() (int, string) { return 0, “OK” } – can return multiple values
• type Name struct { name int } – when need to create a type. DOn’t need a lot of them
• s := MyStruct{value}
• s := MyStruct{name: value}
• fun (s MyStruct) function() {} – attaches function to a struct. Can then call on a MyStruct variable

Scope

• uppercase symbol means public
• lowercase symbol means private (to package)

Data structures

• var strs = []string{“a”, “b”} or strings := []string {“a”, b”}
• mapOfValues := make(map([string]int)) or mapOfValues := map[string]int {“a” : 1}
• mapOfValues[“foo”] = 1
• var array [4]int – ust be exactly 4 ints

Concepts

• Can create nested functions
• No classes or methods
• Constructors are automatic
• Get compilation error for unused code
• Only one keyword for loops. Use “for” and omit sections to make while loop
• No exceptions
• float64 data type

Features unique to Go

• The interface{} type is roughly equivalent to java.lang.Object. “Just” need to ensure provide implementation of the method.
• can use return type “error” and call errors.New to indicate an error. Can return nil if no error. Assign error to variable named _ to indicate to compiler that intentionally ignoring. [I don’t get how this is better; it seems like there would be error handling everywhere]
• Type cloning: type foo int – treat foo as int. However, cannot pass foo when int expected
• Type alias: type foo = int – treat foo as int, but can pass foo when int expected
• gRPC – use instead of REST. Remote procedure call framework. gRPC works with many languages including Java and Go.
• web assembly – can run go code on the browser. Can compile Go code into web assembly

Performance

• Runs faster than Java with Java defaults. Not comparing to Graal for native code
• When build code, runs faster than simply running it because interpreted

Links

• gobyexample.com
• play.golang.org -run Go online
• github.com/cdarwin/go-koans
• golang.org/cmd/gofmt – automatically formats code according to go standards. Developers do not get to choose or argue.

My take

I learned a lot and it was easy to follow. I can feel my brain getting full.