How to efficiently find all the files matching a particular suffix in all the directories?

I need to recursively find all the files in a directory which can have lot of sub-directories too. I was wondering if there is any way it can only give me *.json files only?
I have below method which does the job and gives me all files recursively in all the directories but I am not sure whether I am doing it right by using HasSuffix here. I am new to golang so I not sure if there is any better or efficient way to do this.

func WalkDir(root string) ([]string, error) {
	var files []string
	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if !info.IsDir() && strings.HasSuffix(path, "json") {
			files = append(files, path)
		}
		return nil
	})
	return files, err
}

Also how can I modify above method so that it can give me all the files matching *.json or *.txt suffix. Basically it should be able to work with suffix array and give me all files matching that. What is the efficient way to do this?

You probably want to ensure the dot (.) is present before the file suffix too.

Also as noted by @maxm, WalkDir is preferred according to the docs:

> Walk is less efficient than WalkDir, introduced in Go 1.16, which
> avoids calling os.Lstat on every visited file or directory.

To check for a match of multiple suffixes you can try:

func WalkDir(root string, exts []string) ([]string, error) {
    var files []string
    err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
        if d.IsDir() {
            return nil
        }

        for _, s := range exts {
            if strings.HasSuffix(path, "."+s) {
                files = append(files, path)
                return nil
            }
        }

        return nil
    })
    return files, err
}

And to use:

files, err := WalkDir("/home", []string{"json", "txt"})