C # compare the two time sizes, cf
C # compare the two time sizes
DateTime t1 = Convert. ToDateTime ("23:59:00 ");
DateTime t2 = Convert. ToDateTime ("00:01:00 ");
TimeSpan ts = t2-t1;
Int ss = Convert. ToInt32 (ts. TotalMinutes );
TextBox1.Text = ss. ToString ();
In C language ^ how to use a1 = 0x01; // 0000 0001
A2 = 0x00; // 0000 0000
A3 = 0x03; // 0000 0011
A4 = 0x02; // 0000 0010
B1 = a1 ^ a2; // 0000 0001
B2 = a1 ^ a3; // 0000 0010
B3 = a1 ^ a4; // 0000 0011
^ XOR operator. The bitwise value is 0 and the difference is 1. See the example above.
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Examples of simple and practical problems:
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======= A ======= B =========
There are two circuits on the top. The two switches are a and B respectively. The opening status is \ [1], and the closing status is/[0].
If both circuits are enabled or disabled.
If a turns on [1], B turns off [0], and circuit 1 Powers on
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If a disables [0], B enables [1], and circuit 2 powers on.
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In summary, the circuit fails in the and B states simultaneously [0]. When a and B are different, the power is charged [1].
C Language & |! What is the? & operator used to extract the address of a variable.
For example, if you define a variable, the system will allocate a space in the memory during compilation.
The location of the space in the memory is its address. & Extract its address.
E. g int a; assign an address to it during compilation, for example, 2000; & a is 2000.
If an integer pointer Variable p, p = & a; is defined, the address 2000 of a is assigned to p. P = 2000 after running.
Another example is scanf ("% d", & a). When you enter 3, it first knows the address of a according to & a, and finds the space of a in the memory by the address, write 3 to this space.
* Is a pointer operator, which is opposite to &. It extracts the value of a Variable Based on the address of the variable.
For example, * the value of a is 3 of variable.
The following is a summary of the pointer used in the definition and description.
Int * p; defines a pointer to integer data.
Int * p [n]; defines the pointer array p, which consists of n pointer elements pointing to integer data.
Int (* p) [n]; p is the pointer variable pointing to a one-dimensional array containing n elements.
Int * p (); p is the function that returns a pointer pointing to integer data.
Int (* p) (); p is the pointer to the function. This function returns an integer value.
Int ** p; p is a pointer variable that points to an integer Data Pointer variable.
If you want to learn more about the system, you can refer to tan haoqiang's c Programming (the third edition), which is easy to understand. Is a good C language learning material.
