C # character conversion, value assignment, Relational operators, logical operators, bitwise operations, and type conversion,

C # character conversion, value assignment, Relational operators, logical operators, bitwise operations, and type conversion,
I. Conversion of Characters

Corresponding ASCALL Value

0-48

A-65

A-97

Example charch = 'a ';

Console. WriteLine (int) ch); // output 97

Ii. Value assignment

// When writing code variables, you must get into the habit of defining names that conform to actual meanings, such as age, Not a or B.

Example: ①// 1 + 2 + 3 + 4 + 5

Intresult = 0;

Result + = 1; // result = result + 1;

Console. WriteLine (result );

Result + = 2; // result = result + 2;

Console. WriteLine (result );

Result + = 3; // result = result + 3;

Console. WriteLine (result );

Result + = 4; // result = result + 4;

Console. WriteLine (result );

Result + = 5; // result = result + 5;

Console. WriteLine (result );

②// Multiplication

Intnum3 = 4;

Intnum4 = 5;

Num3 * = num4; // num3 = num3 * num4

Console. WriteLine (num3 );

③ // Subtraction

Note: intnum5 = 9;

Intnum6 = 5;

// Num5-= num6; // num5 = num5-num6

// Console. WriteLine (num5 );

// You can directly write it like this

Console. WriteLine (num5-= num6 );

④ // Division

Num5 = 10;

Num6 = 6;

Num5/= num6; // num5 = num5/num6;

Console. WriteLine (num5 );

⑤ // Module, etc.

Num3 = 9;

Num4 = 5;

Num3 % = num4; // num3 = num3 % num4;

Console. WriteLine (num3 );

Similar to num1 = num1 + 1; it can be written as num1 + +;

Similar to num1 = num1 + num2, you can write it as num1 + = num2;

Iii. Relational operators (comparison operators)

1,// The Value assignment has the lowest priority

Boolret = 4 = 3;

Console. WriteLine (ret );

//> = Indicates that the value is greater than or equal to either of the two.

Ret = 4> = 3;

Iv. logical operators (logic)

1. // logic and &&

// Logic or |

// The logic is not!

2. // examples, 3, and 4 are smaller than 5. It is best to write code with spaces to form a habit.

// Logic and &&

Boolret = 3 <5 & 4 <5; // symbol priority in the expression <& =

Console. WriteLine (ret); // outputs true

3 // logical or |

Ret = 3 <5 | 4 <5;

Console. WriteLine (ret );

4 // The logic is not!

Ret = true;

Ret =! Ret;

Console. WriteLine (ret );

Summary:

①* Expression 1 & Expression 2: When expression 1 and expression 2 are both true, the calculation result is true. If either of the two is false

* Logic and short circuit: If expression 1 is incorrect, expression 2 is no longer executed. Therefore, you can put the first error-prone one for optimization.

②* Expression 1 | expression 2: It is false when expression 1 and expression 2 are not true,

* If one of them is correct, the result is true;

* Logical or short circuit: If expression 1 is correct, expression 2 is not executed.

③* Non-logical: gets the opposite value.

5. bitwise operation (digit-based)

1Console. WriteLine (6 & 11); // bitwise AND & no space, this is calculated, logic and & Space

2Console. WriteLine (6 | 11); // By bit or |

3Console. WriteLine (~ 6); // non-~ by bit ~

4// Exclusive or

Intnum1 = 6;

Intnum2 = 11;

// 13 6 11

Num1 = num1 ^ num2;

// 6 13 11

Num2 = num1 ^ num2;

// 11 13 6

Num1 = num1 ^ num2

5/*

* Bit operation summary:

* Bitwise AND: the total value of 1 is 1;

* By bit or: The value is 0 only when all values are 0;

* Bitwise non:-(number + 1); that is, add 1 to each number and then reverse it.

* Bitwise OR: the same value is 0, and the difference is 1;

* Remember to move left to right. The result of moving one digit to the left is twice the original value. <shifted to the left.

The result of moving one digit to the right is 1/2 times that of the original one.> shifted to the right.

Vi. type conversion

1,// Console. WriteLine (int. MaxValue );

// Console. WriteLine (int. MinValue );

Console. WriteLine (int. MaxValue + "" + int. MinValue); // The value range is small.

Console. WriteLine (long. MaxValue + "" + long. MinValue); // large range

2,

①// Implicit type conversion, small range conversion to large range type

Intnum_int1 = 100;

Longnum_long1 = num_int1; // The int type can be put in long.

Console. WriteLine (num_long1 );

②// An error will be reported and then forced conversion plus (type)

// Force type conversion

// Large scope to small scope(Because data may be lost)

Longnum_longg2 = 300;

// Force type. Be careful. data may be lost.

Intnum_int2 = (int) num_long2; // type (int) added during conversion)

Console. WriteLine (num_int2 );

③Charch = 'a ';

Console. WriteLine (int) ch );

Charch1 = 'B ';

// The character is also a number, and each character corresponds to a number

Console. WriteLine (ch + response );

// Character concatenation display

Console. WriteLine ("+ ch + response); // display AB

Console. WriteLine (ch + "" + response); // You can also

Stringstr = ch + keys + "";

Console. WriteLine (str); // display 195

// Verify that the characters and numbers correspond one to one.

Console. WriteLine (int) 'A'); // display 65

Console. WriteLine (char) 65); // display