Letter shuffler

This tool rearranges all letters in the given string, word, sentence, or text. It uses the Fisher-Yates-Knuth shuffling algorithm to do the job. This algorithm generates random permutations of finite sets of characters with the same probability distribution. For a string of "n" letters, there are 1×2×3×…×(n-1)×n (n factorial) possible unique letter permutations. The Fisher and Yates' method rearranges each letter individually but you can also move more than one letter at a time. With the letter grouping option, you can combine several letters into a group and move them as a whole unit. For example, if the input text is "orange" and you enter a group size of 2, then you'll get three double-letter units: "or", "an", "ge". For these units, there are 6 (1×2×3 = 3 factorial) possible permutations and they are: "or-an-ge", "or-ge-an", "an-or-ge", "an-ge-or", "ge-an-or", "ge-or-an". The program allows you to shuffle letters in any text of any format, shape, size, and type. It's equipped with five radio options that define the areas where letter mixing should occur. There's the "Shuffle Letters In Words" mode, which finds individual words in the text and randomizes the letter order in them (spaces and punctuation symbols don't move in this mode). The "Shuffle Letters In Lines" mode works with multiline texts and allows you to mix characters in each line separately. The "Shuffle Letters In Sentences" mode splits the given text into sentences and shuffles the letters in each of them. In this mode, the sentence structure doesn't change. The "Shuffle Letters In Paragraphs" mode works with paragraphs of text (which are separated by one or more empty lines) and shuffles the characters within each paragraph individually. This mode keeps the paragraph structure. The last mode is "Shuffle Letters Everywhere" and it shuffles absolutely all letters and symbols of the input data, along its entire length. For convenience, you can also turn on the "Make Letters Lowercase" option. It'll make all the letters in the output lowercase and hide the positions of the original uppercase letters. Additionally, you can use the "Get Unique Letters Only" option, which removes repeated letters and shuffles only unique letters. And with the "Remove Punctuation" option, you can remove unneeded punctuation marks and other characters that you don't want to have in the output by listing them in the cleanup option. Randomabulous!