Go Program to Convert Character to Lowercase

In this Go Program, to convert the character to lowercase, we used IsLetter to check the character is an alphabet. Next, we used the unicode ToLower function (lw := unicode.ToLower(upch)) that converts the uppercase characters to lowercase.

package main

import (
    "bufio"
    "fmt"
    "os"
    "unicode"
)

func main() {

    reader := bufio.NewReader(os.Stdin)

    fmt.Print("Enter Character to Convert into Lowercase = ")
    upch, _, _ := reader.ReadRune()

    if unicode.IsLetter(upch) {
        lw := unicode.ToLower(upch)
        fmt.Printf("The Lowercase Character of %c = %c\n", upch, lw)
    } else {
        fmt.Printf("Please Enter a Valid Alphabet\n")
    }
}

Go Program to Convert Uppercase Character to Lowercase

In this uppercase to lowercase convert example, we cast the given byte character to Rune (lw := unicode.ToLower(rune(upch))) and then use the ToLower function.

package main

import (
    "bufio"
    "fmt"
    "os"
    "unicode"
)

func main() {

    reader := bufio.NewReader(os.Stdin)

    fmt.Print("Enter Character to Convert into Lowercase = ")
    upch, _ := reader.ReadByte()

    if unicode.IsLetter(rune(upch)) {
        lw := unicode.ToLower(rune(upch))
        fmt.Printf("The Lowercase Character of %c = %c\n", upch, lw)
    } else {
        fmt.Printf("Please Enter a Valid Alphabet\n")
    }
}

SureshMac:GoExamples suresh$ go run charToLower2.go
Enter Character to Convert into Lowercase = D
The Lowercase Character of D = d
SureshMac:GoExamples suresh$ go run charToLower2.go
Enter Character to Convert into Lowercase = 1
Please Enter a Valid Alphabet

This Golang Convert Character to an Uppercase Program uses the ASCII codes (if upch >= 65 && upch <= 90) to find the character is uppercase. If true, we added 32 (lw := upch + 32) to the ASCII value to convert uppercase to the lowercase character.

package main

import (
    "bufio"
    "fmt"
    "os"
)

func main() {

    reader := bufio.NewReader(os.Stdin)

    fmt.Print("Enter Character to Convert into Lowercase = ")
    upch, _ := reader.ReadByte()

    if upch >= 65 && upch <= 90 {
        lw := upch + 32
        fmt.Printf("The Lowercase Character of %c = %c\n", upch, lw)
    } else {
        fmt.Printf("Either You entered the Lowercase Char or Inalid Alphabet\n")
    }
}

SureshMac:GoExamples suresh$ go run charToLower3.go
Enter Character to Convert into Lowercase = q
Either You entered the Lowercase Char or Inalid Alphabet
SureshMac:GoExamples suresh$ go run charToLower3.go
Enter Character to Convert into Lowercase = B
The Lowercase Character of B = b

In this example, We used the A and Z within the If condition (if upch >= ‘A’ && upch <= ‘Z’) to find the uppercase character. If True, we are adding 32 to its ASCII value.

package main

import (
    "bufio"
    "fmt"
    "os"
)

func main() {

    reader := bufio.NewReader(os.Stdin)

    fmt.Print("Enter Character to Convert into Lowercase = ")
    upch, _ := reader.ReadByte()

    if upch >= 'A' && upch <= 'Z' {
        lw := upch + 32
        fmt.Printf("The Lowercase Character of %c = %c\n", upch, lw)
    } else {
        fmt.Printf("Either You entered the Lowercase Char or Inalid Alphabet\n")
    }
}

SureshMac:GoExamples suresh$ go run charToLower4.go
Enter Character to Convert into Lowercase = N
The Lowercase Character of N = n
SureshMac:GoExamples suresh$ go run charToLower4.go
Enter Character to Convert into Lowercase = j
Either You entered the Lowercase Char or Inalid Alphabet