1, decimal integer constant
Integer constants in this format can only have numbers from 0 to 9, and can have positive and negative signs. For example:
0 1 364 28 -34
2. Octal integer constant
Integer constants in this format are octal numeric strings starting with the number 0. Where the numbers are 0 ~ 7. For example:
0 1 1 1 decimal 73, 0 1 1 decimal 9,0123 decimal 83,
3. Hexadecimal integer constant
Integer constants in this format are hexadecimal numeric strings starting with 0x or 0X(x is capitalized). Where each number can be 0 ~ 9, a ~ f or a ~
Numbers or English letters in F. For example:
0x 1 1 decimal 17, 0Xa5 decimal 165, 0x5a decimal 90,