What are the logical operators of DOS?

Boolean logic operators are used to represent a logical relationship between two search terms to form a concept.

There are three commonly used Boolean logic operators, which are logic and (and), logic or (or), logic.

In formal logic, logical operators or logical conjunctions connect statements into more complex and complex statements. For example, suppose there are two logical propositions, which are:"It's raining"with"I'm in the house", we can compose them into complex propositions"It's raining, and I'm in the house"or"It's not raining"or"If it's raining, then I'm in the house"。A new statement or proposition that combines two statements is called a compound statement or compound proposition.

Logical not.

Logical and.

Logical or. The priority is: not and or.

Siblings from left to right.

Enter cmd in the runtime, enter dos, enter cd to enter the directory of the c drive, and then enter dir to get the list of c drive files. Enter cd windows to enter the windows folder, and enter tree to mean directory tree. Enter d; Go to the D drive.

Syntax: find start directory Find Condition action.

1 Comparison operator.

Comparison Operator Meaning.

|, the logical operator includes &&&du!. where &&& and ||It's double zhi

The purpose operator DAO

The actual version is now logical and, logical or right.

is a monocular operator that implements logical non.

Variables or expressions that result in boolean can be combined into logical expressions by logical operators. Logical operators && ! Follow Table 2 for logical operations.

The priority of the logical operator is: ! The highest level of operation, &&& is higher than ||Operation.! The operator takes precedence over the arithmetic operator, while &&& and ||Arithmetic is lower than relational operator.

The binding directions are: logical NOT (monocular operator) has right binding, logical AND logic OR (binocular operator) has left binding.

Symbol copy meaning.

Less than. Raid is greater than.

less than or equal to.

Greater than or equal to.

Amount. = Not equal.

And. du (and)

and (and).

or zhi (or).

or (or).

XOR Unique or (XOR).

Not (not).

Combine DAO result operators. and...or...xor

To put it simply. and: True when the same is true.

or: False when the same is false.

xor: The same is false.

|With, or, non-or, different or luck are self-calculated. 1.And.

2.or0|bai|0 =0

3.Non (anti-du).

4.XOR.

True or false

dao = true.

False True = True.

False False = False.

True True = False.

Logical operators are used to merge or take non-or || of expressions that contain relational operatorsFor example, in two, as long as one is true, then the result is established and &&& For example, in two, two are established at the same time, then the result is true, otherwise it is not established! It means the opposite, it's not this, it's that.

There is no such thing as "or" and "and" in a single if statement. The corresponding judgment can be achieved by nesting or combining multiple if statements. For example:

With: if condition a if condition B doing something or: if condition a doing somethingif condition B doing something

if command.

If indicates that the specified conditions are met and thus decide to execute a different command. There are three formats:

1、if "parameters" == "Strings"Pending commands.

If the parameter is equal to the specified string, the condition is true, run the command, otherwise run the next sentence. (Note that there are two equal signs).

Such as"%1"=="a" format a:

if =={} goto noparms

if =={} goto noparms

2. if (not) exist filename The command to be executed.

If there is a specified file, the condition is true, run the command, otherwise run the next sentence.

If exist edit

3. if errorlevel if not errorlevel Number Command to be executed.

If the return code is equal to the specified number, the condition holds, run the command, otherwise run the next sentence.

Such as if errorlevel 2 goto x2

When the DOS program runs, it will return a number to the DOS, which is called the error code ErrorLevel or return code, and the common return code is .

A symbol used for logical budgeting, generally used to determine the intersection and union of two variables, generally returning a Boolean value, and its operation principle is the same as that of logical operations in mathematics, including:

and: logic and operation;

or: logic or operation;

net: logical non-operational.

Logical operators mainly include three, and or not, this is the same concept as in mathematics, two conditions to do and operate, as long as one is false, the result is false, true and false are false, false and true are false, false and false are false, and only one true and true is true. And the operation is that as long as one is true, it is true, true or false is true, false or true is true, true or true is true, only false or false is false, and finally non-operation is either true or false.

Boolean Logical Operator Meaning.

Logic with. Logic or.

XOR. Short circuit or.

Short circuit with. Logical inverse. = Logic & Assignment (shorthand for assignment).

Logic or assignment (shorthand for assignment).

XOR assignment (shorthand form of assignment).

Equal. = Not equal.

The ternary operator (if-then-else) Boolean logic operator "&" does the same thing with Boolean values as they do with integer bits. logical operator "!".

The result represents the opposite state of the boolean value: !true == false and! false == true