C # The regular expression in the regular expression takes only the first N matching results,

C # The regular expression in the regular expression takes only the first N matching results,

The Regex. Matches method can be used to obtain all matching results corresponding to the specified regular expression. Sometimes, there may be thousands of matching results. Considering the performance efficiency, you only need to extract the first N matching results. The following code demonstrates the practice:

Requirement: Take the first three values (connected numbers) in the string ).

[Csharp]View plaincopy

1. Match match = Regex. Match ("12ab34de567ab890", @ "\ d + ");
2. For (int I = 0; I <3; I ++)
3. {
4. If (match. Success)
5. {
6. Response. Write (match. Value + "<br/> ");
7. Match = match. NextMatch ();
8. }
9. }

Output:

12

34

567

& In C Language

& Can be used as the bitwise AND or address fetch Operator
The following describes two usage methods:
1. bitwise and operation bitwise AND operator "&" are binary operators. Its function is the binary phase corresponding to the two numbers involved in the operation. The result bit is 1 only when the two binary numbers are 1. Otherwise, the result bit is 0. The number of involved operations is supplemented.
For example, 9 & 5 can be written as follows: 00001001 (Binary complement of 9) & 00000101 (Binary complement of 5) 00000001 (Binary complement of 1) Visible 9 & 5 = 1.
Bitwise AND operations are usually used to clear some bits or retain some bits. For example, if a clears the high eight bits of 0 and retains the low eight bits, it can be used as a & 255 operation (255 of the binary number is 0000000011111111 ).
2. Get the address
& As The unary operator, the result is the address of the right operation object.
For example, & x returns the address of x.
The address itself is an abstract concept used to indicate the logical location of an object in the memory.

& In C Language

& Can be used as the bitwise AND or address fetch Operator
The following describes two usage methods:
1. bitwise and operation bitwise AND operator "&" are binary operators. Its function is the binary phase corresponding to the two numbers involved in the operation. The result bit is 1 only when the two binary numbers are 1. Otherwise, the result bit is 0. The number of involved operations is supplemented.
For example, 9 & 5 can be written as follows: 00001001 (Binary complement of 9) & 00000101 (Binary complement of 5) 00000001 (Binary complement of 1) Visible 9 & 5 = 1.
Bitwise AND operations are usually used to clear some bits or retain some bits. For example, if a clears the high eight bits of 0 and retains the low eight bits, it can be used as a & 255 operation (255 of the binary number is 0000000011111111 ).
2. Get the address
& As The unary operator, the result is the address of the right operation object.
For example, & x returns the address of x.
The address itself is an abstract concept used to indicate the logical location of an object in the memory.