Why can you type by holding down the numbers on the alt keypad?

Characters must be encoded before they can be processed by a computer. The default encoding used by computers is the internal code of the computer. Early computers used 7-bit ASCII encoding, and to process Chinese characters, programmers designed GB2312 for Chinese Simplified Chinese and BIG5 for Chinese Traditional.

From ASCII, GB2312, GBK to GB18030, these encoding methods are backward compatible, i.e. the same character always has the same encoding in these schemes, and the later standard supports more characters. In these codecs, English and Chinese can be handled uniformly.

Therefore, if you press "alt + number on the keypad", it is equivalent to converting the encoding into characters, for example, if the ASCII code of A is 65, you press "Alt+65" to enter A.

ascii american standard code for information interchange

Define the English letters or numbers or symbols represented by one hundred and twenty-eight numbers from 0 to 127, and all computers using ASCII can read the same document with each other without different results and meanings. Since only 7 bits can represent numbers from 0 to 127, most computers use 8 bits to access character sets, so numbers between 128 and 255 can be used to represent another set of 128 symbols, called extended ascii

Really, I didn't find out before. It's not an ASCII code, and I didn't get out of A when I pressed 65.

In fact, the Windows operating system has a function that is to hold down the Alt key.

Add the numbers in the numeric keypad on the right to output the corresponding characters.

ASCII codes use a specified 7-bit or 8-bit binary number.

to represent 128 or 256 possible characters. The standard ASCII code, also known as the basic ASCII code, uses 7-digit binary numbers (the remaining 1-digit binary is 0) to represent all uppercase and lowercase letters, numbers 0 through 9, punctuation, and in American English.

special control characters used.

The practical use of alt plus keypad numbers is ASCII**, which is a kind of computer internal code. From 0 to 127 represent different commonly used letters or symbols.

For example, if you enter alt+29482 in QQ, the word "pig" will come out, but if you enter it in this place, there will be *, which is determined by the different encodings used for each program or ** and system.

ASCII Table.