The sample codes listed is very confusing. I am modifying them to make sure it works. I still don't have a good handle / understanding of class. What can't we just use function()???

I think one of the features of PHP is to make it class/object oriented. To do so, you need to understand Class and Object and how they are used. I will spent more time with this to make sure I understand what I am doing. This is a sample ... I created a class called Dog and calling it from outside.

Encoding it make it safer.

This is another high level function of PHP. I am starting to feel like PHP is a 4th generation language ... if you know what I mean.

Another string functions provided PHP that I used to have to write it myself.

This is another function that I used to write as a subroutine in BASIC. I don't know if I call PHP a programming langue. I nishi day 14 with this function.

This is a very useful functions. substr_count() sunstr() subset_replace()

Finding the text within the sentence is a hand function. Like sort(), this function used to require people to write in the program.

Understanding ASXCII value and string length will come in handy.

It compares two strings and return value based on the result. If it returns 0 ... it is a match.