The floating suffix f, l, and exponent indicate whether the degree of attention is within the range;
Characters and strings mainly focus on whether escaped characters are legal or not;
A: Commas are not allowed in integers;
B: Scientific notation means 1.5 times the quadratic of 10, because the exponential part of scientific notation can only be an integer.
The c: \ symbol is an escape character, followed by other symbols to represent specific characters, so you can write back quotation marks here without following anything;
D: The string constant is two consecutive characters, the ascii code of 1 character is 7, the ascii code of the second character is 0 as the ending symbol of the string, and 1 character is the bell symbol, which will make the default speaker sound when outputting.
Extended data:
A string constant is a sequence of characters enclosed in a pair of double quotes.
Character constants can be assigned to character variables, such as "char b =' a", but you can't assign string constants to character variables, and you can't assign string constants!
For example, the following are legal string constants:
"Hello." , "China", "a", "123.45 USD", "c programming", "a\\n", "123" and ""are string constants.
Storage: The characters in the string are sequentially stored in a continuous area in memory, and the empty character' \ 0' is automatically appended to the end of the string as the ending symbol of the string. Therefore, a string containing n characters should occupy (n+ 1) bytes in memory.
Baidu Encyclopedia-String Constant