How to Map a Rune to the Specified Case in Golang?


If you're working with runes in Golang, you may need to map them to a specified case. This can be useful when dealing with text that contains both uppercase and lowercase characters, or when you need to convert text to a specific case for formatting purposes. In this article, we'll go over how to map a rune to a specified case in Golang, and provide some helpful tips for optimizing your code.

What is a Rune in Golang?

Before we get into mapping runes to a specific case, it's important to understand what a rune is in Golang. In Golang, a rune is an alias for the int32 data type, and represents a Unicode code point. In other words, a rune is a single character in a string, and can be used to represent any character from any language.

Mapping a Rune to a Specific Case

To map a rune to a specific case in Golang, you can use the built-in unicode package. Specifically, you can use the ToUpper and ToLower functions to convert a rune to uppercase or lowercase, respectively.

Example

Here's an example −

package main

import (
   "fmt"
   "unicode"
)

func main() {
   r := 'a' // The character 'a' as a rune
   upper := unicode.ToUpper(r) // Convert to uppercase
   lower := unicode.ToLower(r) // Convert to lowercase

   fmt.Printf("Original: %c\nUppercase: %c\nLowercase: %c\n", r, upper, lower)
}

Output

Original: a
Uppercase: A
Lowercase: a

In this example, we define a rune 'a' and use the ToUpper and ToLower functions to convert it to uppercase and lowercase, respectively. We then print the original rune, as well as the converted uppercase and lowercase runes.

Optimizing Your Code

While the above code works perfectly fine, there are a few tips you can use to optimize your code and make it more efficient. Here are some things to keep in mind −

  • Use the Rune Literal Syntax − Instead of using the unicode package to convert a character to a rune, you can use the rune literal syntax. For example, instead of r := 'a', you can use r := rune('a'). This is slightly more efficient since it avoids the overhead of calling the unicode package.

  • Avoid Repeated Calls to the Same Function − If you need to map multiple runes to a specific case, it's more efficient to call the ToUpper or ToLower function once and store the result in a variable. You can then use this variable to map multiple runes to the same case.

Example

For example −

package main

import (
   "fmt"
   "unicode"
)

func main() {
   toUpper := unicode.ToUpper // Store the ToUpper function in a variable

   r1 := 'a'
   r2 := 'b'

   upper1 := toUpper(r1) // Map r1 to uppercase
   upper2 := toUpper(r2) // Map r2 to uppercase

   fmt.Printf("%c%c", upper1, upper2)
}

Output

AB

In this example, we store the ToUpper function in the toUpper variable and use it to map two runes to uppercase. This is more efficient than calling the ToUpper function twice.

Conclusion

Mapping a rune to a specific case in Golang is a simple task that can be accomplished using the built-in unicode package. By using the tips outlined in this article, you can optimize your code and make it more efficient. With these tools, you'll be able to easily work with text that contains both uppercase and lowercase characters, and convert it to the specific case you need for formatting purposes.

Updated on: 08-May-2023

119 Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements