How to capitalise first letter of each word in a string in go manually?-CodePudding

I am trying to write a function manually that capitalises the first letter of each word in a string. For example: "My dog is cute! I love my dog 4ever" to "My Dog Is Cute! I Love My Dog 4ever". I would be glad if you can help me.

func Capitalize(s string) string {
L := ToLower(s)
runeL := []rune(L)
len := len(runeL) - 1
Lnew := Concat(ToUpper(string(L[0])), string(runeL[1:len]))
LnewS := []rune(Lnew)
newstrings := []rune{}
for i := range LnewS {
    if IsAlpha(string(LnewS[i])) == true {
        newstrings = append(newstrings, LnewS[i])
    } else {
        newstrings = append(newstrings, LnewS[i])
        if LnewS[i 1] == rune(32) {
            newstrings = append(newstrings)
        }
        if IsLower(string(LnewS[i 1:])) {
            LnewS[i 1] = LnewS[i 1] - rune(32)
        }
    }
}
return string(newstrings)

}

CodePudding user response：

In a letter to Robert Hooke in 1675, Isaac Newton made his most famous statement: “If I have seen further it is by standing on the shoulders of Giants”.

Let's follow Newton's advice and read,

The C Programming Language, Second Edition
Brian W. Kernighan and Dennis M. Ritchie

In particular, read,

1.5.4 Word Counting

The section introduces a key concept, state variables: "The variable state records whether the program is currently in a word or not."

If we apply that insight to your problem then we get something like this,

package main

import (
    "fmt"
    "unicode"
)

func Capitalize(s string) string {
    rs := []rune(s)
    inWord := false
    for i, r := range rs {
        if unicode.IsLetter(r) || unicode.IsNumber(r) {
            if !inWord {
                rs[i] = unicode.ToUpper(r)
            }
            inWord = true
        } else {
            inWord = false
        }
    }
    return string(rs)
}

func main() {
    s := "My dog is cute! I love my dog 4ever"
    fmt.Println(s)
    t := Capitalize(s)
    fmt.Println(t)
}

https://go.dev/play/p/ZIkg44o8Brp

My dog is cute! I love my dog 4ever
My Dog Is Cute! I Love My Dog 4ever

CodePudding user response：

You can use the strings package with its title function to capitalize first letter of each word. An example of it can be seen below.

package main

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


func main() {
    var strInput string
    fmt.Println("Enter a string")
    scanner := bufio.NewScanner(os.Stdin)
    if scanner.Scan() {
        strInput = scanner.Text()
    }

    res := strings.Title(strInput)
    fmt.Println(res)
}

If you wanna do it manually, write an algorithm where

Checks the entire index of the string
If an index is the first index or it's an alphabet after a space, change that index alphabet into uppercase, and it should work