How to convert a string in uppercase in Golang?

In Go language, strings are different from other languages like Java, C++, Python, etc. It is a sequence of variable-width characters where each and every character is represented by one or more bytes using UTF-8 Encoding.
In Go string, you are allowed to convert a string in the uppercase using the following functions. All these functions are defined under strings package, so you have to import strings package in your program to access these functions:

1. ToUpper: This function is used to convert the given string elements to uppercase. Or in other words, this function returns a copy of the given string in which all the Unicode characters are mapped into uppercase.

Syntax:

func ToUpper(str string) string

Here, str represents the string which you want to convert to uppercase. Let us discuss this concept with the help of an example:

Example:

// Go program to illustrate how to convert
// the given string into uppercase
package main

import (
    "fmt"
    "strings"
)

// Main method
func main() {

    // Creating and initializing string
    // Using shorthand declaration
    str1 := "WelcomE, GeeksforGeeks**"
    str2 := "$$This is the, tuTorial oF Golang##"
    str3 := "HELLO! GOLANG"
    str4 := "uppercase conversion"

    // Displaying strings
    fmt.Println("Strings (before):")
    fmt.Println("String 1: ", str1)
    fmt.Println("String 2:", str2)
    fmt.Println("String 3:", str3)
    fmt.Println("String 4:", str4)

    // Converting all the string into uppercase
    // Using ToUpper() function
    res1 := strings.ToUpper(str1)
    res2 := strings.ToUpper(str2)
    res3 := strings.ToUpper(str3)
    res4 := strings.ToUpper(str4)

    // Displaying the results
    fmt.Println("\nStrings (after):")
    fmt.Println("Result 1: ", res1)
    fmt.Println("Result 2:", res2)
    fmt.Println("Result 3:", res3)
    fmt.Println("Result 4:", res4)
}

Output:

Strings (before):
String 1:  WelcomE, GeeksforGeeks**
String 2: $$This is the, tuTorial oF Golang##
String 3: HELLO! GOLANG
String 4: uppercase conversion

Strings (after):
Result 1:  WELCOME, GEEKSFORGEEKS**
Result 2: $$THIS IS THE, TUTORIAL OF GOLANG##
Result 3: HELLO! GOLANG
Result 4: UPPERCASE CONVERSION

2. ToTitle: This function is used to convert the string elements to title case. Or in other words, this function returns a copy of the given string in which all the Unicode characters are mapped into title case.

Syntax:

func ToTitle(str string) string

Here, str represents the string which you want to convert to title case. Let us discuss this concept with the help of an example:

Example:

// Go program to illustrate how to convert
// the given string into title case
package main

import (
    "fmt"
    "strings"
)

// Main method
func main() {

    // Creating and initializing string
    // Using shorthand declaration
    str1 := "WelcomE, GeeksforGeeks**"
    str2 := "$$This is the, tuTorial oF Golang##"
    str3 := "HELLO! GOLANG"
    str4 := "uppercase conversion"

    // Displaying strings
    fmt.Println("Strings (before):")
    fmt.Println("String 1: ", str1)
    fmt.Println("String 2:", str2)
    fmt.Println("String 3:", str3)
    fmt.Println("String 4:", str4)

    // Converting all the string into title case
    // Using ToTitle() function
    res1 := strings.ToTitle(str1)
    res2 := strings.ToTitle(str2)
    res3 := strings.ToTitle(str3)
    res4 := strings.ToTitle(str4)

    // Displaying the results
    fmt.Println("\nStrings (after):")
    fmt.Println("Result 1: ", res1)
    fmt.Println("Result 2:", res2)
    fmt.Println("Result 3:", res3)
    fmt.Println("Result 4:", res4)
}

Output:

Strings (before):
String 1:  WelcomE, GeeksforGeeks**
String 2: $$This is the, tuTorial oF Golang##
String 3: HELLO! GOLANG
String 4: uppercase conversion

Strings (after):
Result 1:  WELCOME, GEEKSFORGEEKS**
Result 2: $$THIS IS THE, TUTORIAL OF GOLANG##
Result 3: HELLO! GOLANG
Result 4: UPPERCASE CONVERSION