Why won't this username check work?

Help and Feedback Scripting Support
#1

Here is the code:

	if typing == false then
		if pcall(function() game.Players:GetUserIdFromNameAsync(usernameField.Text) end) == nil then
			errorLine.Visible = true
			errorMessage.Text = "Error: '"..usernameField.Text.."' is not a valid username."
			errorMessage.Visible = true
		end
	end
end)```

Nothing comes in the output. Any ideas?
#2

What type of script is this in?

#3

Using the pcall function returns multiples values (a tuple), a bool indicating if the execution of the function was successful or not, and the results of the function or the error message.

Example:

local success, result = pcall(function ()
    return game.Players:GetUserIdFromNameAsync(usernameField.Text)
end)

if success then
    print(result) -- The UserId
else
    warn(result) -- The error message
end

In your if statement, you’re checking if the first value is nil, which it will never be.
In your pcall function, your also not returning the UserId you got from their name.

#4 
local usernameField = script.Parent
local userInput = game:GetService("UserInputService")
local players = game:GetService("Players")

userInput.InpuBegan:Connect(function(input, typing)
	if typing then
		return
	end
	
	local success, result = pcall(function()
		return players:GetPlayerByUserId(usernameField.Text)
	end)
	
	if success then
		if result then
			local player = result
			print(player.Name)
		end
	else
		warn(result)
		errorLine.Visible = true
		errorMessage.Text = "Error: '"..usernameField.Text.."' is not a valid user ID."
		errorMessage.Visible = true
	end
end)

I filled in the blanks a little but I believe this is what you were trying to do. If you want to find a player based off their username instead then that’s a simple change.

local usernameField = script.Parent
local userInput = game:GetService("UserInputService")
local players = game:GetService("Players")

userInput.InpuBegan:Connect(function(input, typing)
	if typing then
		return
	end
	
	local success, result = pcall(function()
		return players:FindFirstChild(usernameField.Text)
	end)
	
	if success then
		if result then
			local player = result
			print(player.Name)
		end
	else
		warn(result)
		errorLine.Visible = true
		errorMessage.Text = "Error: '"..usernameField.Text.."' is not a valid username."
		errorMessage.Visible = true
	end
end)
#5

Thanks a lot! This worked. I made a couple of my own modifications, but otherwise, thanks for this. Really helped!