while trying to automate keyPress event in a loop, I get the error: "Unrecognized function or variable 'VK_i'

I am trying to automate/simualte the keyboard to automatically generate/type numbers using the java robot class and I running into the following error: Unrecognized function or variable 'VK_i'. Could someone help. Here is my code snippet:

clc; clear; close all;

import java.awt.Robot;

import java.awt.event.*;

import java.awt.event.KeyEvent;

keybrd = java.awt.Robot; %Create a keyboard object

for i = 1:3

%num = num2str(i);

key = java.awt.event.KeyEvent.VK_i;

keybrd.keyPress(key);

keybrd.keyRelease(key);

end

Answer 1

[Voss]

key = java.awt.event.KeyEvent.(sprintf('VK_%d',i));

[Syed Bahrez Nadeem]

Thanks! That worked. In a second for loop of the same code, I am trying to generate/type letters and I am running into indexing errors. Could you please help with this?

import java.awt.Robot;
import java.awt.event.*;
import java.awt.event.KeyEvent;
keybrd = java.awt.Robot; %Create a keyboard object
%Iterate over the length of ext. Generate and press a letter key
ext = 'tf';
for i = 1:length(ext)
    %     inp = strcat('java.awt.event.KeyEvent.VK_',ext(i)); %Ex: 'VK_t'
    %     key = eval(inp); %Evaluates the concatenated string inp and returns it
    %index = num2str(i);
    key = java.awt.event.KeyEvent.(sprintf('VK_%d',ext(num2str(i))));
    keybrd.keyPress(key);
    keybrd.keyRelease(key);
end

[Voss]

key = java.awt.event.KeyEvent.(sprintf('VK_%c',upper(ext(i))));

https://docs.oracle.com/javase/7/docs/api/java/awt/event/KeyEvent.html