The tool should have a user interface that allows the user to enter a string and select a function to perform on the string. The tool should support the following string functions: strlen, strrev, ...

These functions can be used to perform various operations on strings such as finding the length of a string, extracting substrings, finding and replacing substrings, trimming whitespaces, converting ...

To function properly, PHP demands a logical flow of commands. Here are examples of the most common syntax errors in PHP and how to fix them. How to fix missing or mismatched quotes?