Letters Extraction

Extracting letters from text is the process of selecting and isolating individual letters from a text or string. This process can make it possible to reconstruct a subtext or a hidden word.

Take the message ABCDEFGHIJKLMNOPQRSTUVWXYZ, dCode offers different modes for letters extraction:

Take 1 of N letters

Extract a pattern

Extract by mask (1 = preserved letter, 0 = letter ignored)

If needed, start using any letter rather than the first letter.

In addition to the 1 letter out of N (1 letter out of 2, 3 or 4), extracting the letters according to known sequences is possible:

— Sequence of even numbers: 2,4,6,8,10

— Sequence of prime numbers: 2,3,5,7,11

— Fibonacci sequence: 2,3,5,8,13

— Digits of Pi: 3,1,4,1,5,9

etc.

For all these sequences, it is possible to start at the letter 1 or at the letter N.

To isolate 1 letter every N, here is an algorithm // Pseudo-code
function extractLetters1ofN(text, n) {
extracted = ""
textLength = length(text)
for (i = 0 ; i < textLength; i++) {
if (i % N == 0) extracted += text[i]
}
return extracted
}

Although this is not practical, Excel provides functions such as RIGHT() or LEFT() to extract N letters at the beginning or end of words. (dCode is better and recommended)

An acrostic is a poem or message from which certain letters or words can be extracted to give a second meaning to the message.