Hexadecimal regular matching _ regular expressions in programming languages

It is made up of 0-9,a-f. The corresponding relationship with the 10 binary is: 0-9 corresponds to 0-9; A-f corresponds to 10-15; The number of N-ary can be expressed in 0---(N-1) for more than 9 letters A-F.

Which is made up of characters: 012345679ABCDEF

The number 16 in C language must begin with 0x. For example, 0x1 represents a 16 number. and 1 represents a decimal. In addition, such as: 0xff,0xff,0x102a, and so on. The x is not case-sensitive. (Note: 0 of the 0x is the number 0, not the letter O)

So the regular matching of programming languages such as C or C + + is:

Copy Code code as follows:

\b0[xx][0-9a-fa-f]+\b

He can match.

Copy Code code as follows:

0xDEADBEEF
0xdeadbeef
0XDEADBEEF
0Xdeadbeef
0x12345678

Can not match

Copy Code code as follows:

12345678
Deadbeef