Iterating over a Range of Values in GO

How to use the statement to iterate through arrays/slices and iterate through strings.

Iterating through arrays/slices

An array/slice is a collection of items in Go.

For example, OS is an array of three elements.

	var students [3]string
students[0] = "Adam"
students[1] = "Alice"
students[2] = "Ben"

To iterate through each of the elements in the array, you use the for-range loop.

	package main
import (
    "fmt"
)

func main() {
    var students [3]string
    students[0] = "Adam"
    students[1] = "Alice"
    students[2] = "Ben"

    for i, v := range students {
        fmt.Println(i, v)
    }
}

The range keyword returns the following values.

i: The index of the value you’re accessing

v: Each of the values in the Students array.

The previous code snippet prints out the following

	0 Adam
1 Alice
2 Ben

If you don’t want the index, you can use a blank identifier.

	package main

import (
    "fmt"
)

func main() {
    var students [3]string
    students[0] = "Adam"
    students[1] = "Alice"
    students[2] = "Ben"

    for _, v := range students {
        fmt.Println(v)
    }
}

	Adam
Alice
Ben

Same for the value

	package main

import (
    "fmt"
)

func main() {
    var students [3]string
    students[0] = "Adam"
    students[1] = "Alice"
    students[2] = "Ben"

    for i, _ := range students {
        fmt.Println(i)
    }
}

Or you can omit the blank identifier entirely.

	package main

import (
    "fmt"
)

func main() {
    var students [3]string
    students[0] = "Adam"
    students[1] = "Alice"
    students[2] = "Ben"

    for i := range students {
        fmt.Println(i)
    }
}

	0
1
2

Iterating through a string

One of the most common operations involving strings is going through each of the characters in a string and finding the characters you want.
In Go, a string is essentially a read-only slice of bytes.
So, you can use the for-range loop to extract each of the characters in the string.

	package main

import (
    "fmt"
)

func main() {
    for pos, char := range "Hello, From Mars" {
        fmt.Println(pos, char)
    }
}

The above code produces the Unicode code for each character in the string. A Unicode code of 72 is the numerical representation of the H character.

Unicode, which uses numbers to represent characters, is a standard for encoding, representing, and handling text.
It’s a widely used standard for encoding text documents on computers.

When you iterate through a string using the for-range loop, the value you get for each character is the Unicode value.

If you want to get the actual character, use the Printf() function (with the %c format specifier) from the fmt package.

	package main

import (
    "fmt"
)

func main() {
    for pos, char := range "Hello From Mars" {
        fmt.Printf("%d %c\n", pos, char)
    }
}

With the Above Code, Snippet now gets the following output.