How to use data from input in regular expression?

Question

JavaScript

There is a word on the page. For example "Test".
The user must enter into the input the text that is visible on the screen.
If the input is invalid, character input is prohibited.
That is, the user in this example should only be able to enter the word "Test".

let  test = document.querySelector('.test').innerHTML;

ball.forEach(function(item) {
    item.onclick= function(){
        let  input = document.querySelector('.input').value;
        input+=item.innerHTML;
        
        if (регулярное выражение -????) {
          parent.innerHTML += input;
        }
}});

Answer 1

Well, then your regular expression must match the word displayed on the page. In your case - "Test" (without quotes), initialize it with the value test. It will be even easier to do without expressions at all, compare strings and that's it.