PHP Taskbook Level 5.6

Given a form with input. Make it so that after the form is submitted, the entered text remains in the input.

A form with textarea is given. Text with words is entered into it. After sending the form, output the number of words in this text into a paragraph.

A form with an input is given. A year is entered into the input. After sending the form, determine whether a leap year is entered or not and output information about this in a paragraph.

A form with an input is given. The input is a date in the format 2025-12-31. After sending the form, output the day of the week corresponding to this date in a paragraph.

When you enter the page, display in the form ul a list of all years for a hundred years back and forth.