CODEWITHSUNDEEP
stringgo
KainAlive
KainAlive

Reputation: 63

How can I remove the last 4 characters from a string?

I want to remove the last 4 characters from a string, so "test.txt" becomes "test".

package main

import (
    "fmt"
    "strings"
)

func main() {
    file := "test.txt"
    fmt.Print(strings.TrimSuffix(file, "."))
}

Upvotes: 4

Views: 5190

Answers (3)

Abdullah Al Maruf - Tuhin
Abdullah Al Maruf - Tuhin

Reputation: 3779

Though there is already an accepted answer, I want to share some slice tricks for string manipulation.

  1. Remove last n characters from a string

    As the title says, remove the last 4 characters from a string, it is very common usage of slices, ie,

    file := "test.txt"
fmt.Println(file[:len(file)-4]) // you can replace 4 with any n

    Output:

    test

    Playground example.

  2. Remove file extensions:

    From your problem description, it looks like you are trying to trim the file extension suffix (ie, .txt) from the string.

    For this, I would prefer @colminator's answer from above, which is

    file := "test.txt"
fmt.Println(strings.TrimSuffix(file, filepath.Ext(file)))

Upvotes: 4

Shubham Srivastava
Shubham Srivastava

Reputation: 1877

You can use this to remove everything after last "."
go playground

package main

import (
    "fmt"
    "strings"
)

func main() {
    sampleInput := []string{
    "/www/main.js",
    "/tmp/test.txt",
    "/tmp/test2.text",
    "/tmp/test3.verylongext",
    "/user/bob.smith/has.many.dots.exe",
    "/tmp/zeroext.",
    "/tmp/noext",
    "",
    "tldr",
    }
    for _, str := range sampleInput {
        fmt.Println(removeExtn(str))
    }
}

func removeExtn(input string) string {
    if len(input) > 0 {
        if i := strings.LastIndex(input, "."); i > 0 {
            input = input[:i]
        }
    }
    return input
}

Upvotes: 0

colm.anseo
colm.anseo

Reputation: 22037

This will safely remove any dot-extension - and will be tolerant if no extension is found:

func removeExtension(fpath string) string {
        ext := filepath.Ext(fpath)
        return strings.TrimSuffix(fpath, ext)
}

Playground example.

Table tests:

/www/main.js                             -> '/www/main'
/tmp/test.txt                            -> '/tmp/test'
/tmp/test2.text                          -> '/tmp/test2'
/tmp/test3.verylongext                   -> '/tmp/test3'
/user/bob.smith/has.many.dots.exe        -> '/user/bob.smith/has.many.dots'
/tmp/zeroext.                            -> '/tmp/zeroext'
/tmp/noext                               -> '/tmp/noext'
                                         -> ''

Upvotes: 5

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