Go/Strings

Related: Rosalind/Problem 1A

The Go blog: strings, bytes, runes, and characters in Go: https://blog.golang.org/strings

Basics

How strings work in Go

A string in Go is a read-only slice of bytes. A string can hold arbitrary bytes, it is not required to hold unicode/UTF-8/other format. That means that "characters" are not special types in Go; rather, strings refer to bytes.

Indexing a string does not access characters - it accesses the individual bytes, the byte representation of the characters.

String Package

The string package provides several useful string methods. To use it, include it in your imports:

import (
    "strings"
)

Once you import strings, you can call any of the functions provided by the package.

func main() {
    fmt.Println(strings.ToUpper("Hello world!"))
}

The functions provided by the strings package will then be available via, for example, strings.ToUpper().

To make this a little easier, you can do something analogous to Python's import X as Y:

package main

import s "strings"

func main() {
    fmt.Println(s.ToUpper("Hello world!"))
}

List of String Functions

Here is a list of string functions that are available from the string package. These are static methods that operate on string input arguments, they are not methods of the string object itself.

package main

import s "strings"
import "fmt"

var p = fmt.Println
	
func main() {
    p("Contains:  ", s.Contains("test", "es"))
    p("Count:     ", s.Count("test", "t"))
    p("HasPrefix: ", s.HasPrefix("test", "te"))
    p("HasSuffix: ", s.HasSuffix("test", "st"))
    p("Index:     ", s.Index("test", "e"))
    p("Join:      ", s.Join([]string{"a", "b"}, "-"))
    p("Repeat:    ", s.Repeat("a", 5))
    p("Replace:   ", s.Replace("foo", "o", "0", -1))
    p("Replace:   ", s.Replace("foo", "o", "0", 1))
    p("Split:     ", s.Split("a-b-c-d-e", "-"))
    p("ToLower:   ", s.ToLower("TEST"))
    p("ToUpper:   ", s.ToUpper("test"))
    p("Len: ", len("hello"))
}