Note that you expressed the letter P as 0x80 That is you expressed a bit combination using hexadecimal. – due to the above, use the hex forms \x02 and \x03, as it’s less prone to coder error – this ensures genuine numbers ie 221 in this case, aren’t confused by the system – always use leading zeroes to ensure numbers 0 to 99 are shown as a three digit cluster – expressing unprintable bytes in decimal ie \002 and \003 in Lua 5.2 – \x02 means insert the third binary combination, which in this case we consider represents the unprintable control code STX, into the string of bytes – expressing unprintable bytes in hexadecimal in Lua 5.2 Since they can’t be printed, they got names, based on what they did or indicated. They are just abbreviations for a control character meaning End of TeXt or Start of TeXt. So (historically) binary combination 00000010 was assigned STX and 00000011 was assigned ETX, as it was figured these commands could be useful. The combinations could just as easily be assigned to different types of fruit, rather than printable English characters.Īs it turns out, after assigning all the printable characters with a combination, some were left over. In the ASCII table the binary combination for P is assigned the byte combination 80 decimal or 50 hexadecimal. Or in the case of an ASCII table it could specify particular printable characters as used by the English language. Once we have a specific combination expressed in say decimal or in hex, what does that particular combination mean? Well it could just describe a number from 0 to 255. So we can now specify, which byte combination, we are talking about.
In fact, any numbering base can be used, such as octal etc.
A particular combination can typically be expressed as it’s binary contents (00000000 to 11111111) or as a decimal number (0 to 255) or as a hexdecimal number (0 to ff). The confusion probably comes about, due to the ways a byte’s contents can be expressed and also utilised.Ī byte consists of 8 binary bits, allowing 256 combinations of ones & zeroes.
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