How to Get the Unicode Value of a Character in Go: Similar to JavaScript\'s charCodeAt()?

How to Obtain the Unicode Value of a Character in Go, Similar to JavaScript's charCodeAt() Method

JavaScript's charCodeAt() method provides a numeric representation of the Unicode character at a specific index in a string. In Go, handling Unicode values and retrieving character codes requires a slightly different approach.

Understanding Rune in Go

In Go, characters are represented by the rune type, an alias for int32. This means that each character is already a number, unlike JavaScript's strings where characters are represented by numbers accessed through charCodeAt().

Converting a String to Runes

To obtain the numeric Unicode value of a character, convert the string into a slice of runes using []rune(string). This approach allows you to access individual runes within the string.

Using the for Range Loop

Alternatively, you can iterate over the runes in a string using a for range loop. This approach is more efficient than converting the entire string to a slice of runes.

Example Code

The following code demonstrates how to obtain the Unicode value of a character:

<code class="go">package main

import "fmt"

func charCodeAt(s string, n int) int32 {
    i := 0
    for _, r := range s {
        if i == n {
            return r
        }
        i++
    }
    return 0
}

func main() {
    fmt.Println(charCodeAt("s", 0)) // Outputs: 115
    fmt.Println(charCodeAt("absdef", 2)) // Outputs: 115
}</code>

Working with Bytes

If you have guarantees that the string uses characters with codes less than 127, you can directly index the string as bytes instead of runes. In Go, indexing a string retrieves its byte value.

<code class="go">fmt.Println("s"[0]) // Outputs: 115
fmt.Println("absdef"[2]) // Outputs: 115</code>

This approach is more straightforward but may lead to inaccuracies if the string contains multi-byte characters.

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