Auto populate field base on what was entered in another field simultaneously

Question

I was trying to figure out how to auto-populate the input value base on what was entered in another input field using javascript. Here\'s my code:

Answer 1

Create simple html file with two input text box. The first input text box will take the input from the user about a date format and second input text box will display the current date on this format. After the completion of first step, implement date selection library to select a date and format it according to the user input given in first input text b