Where are boolean operators used?

Answer 1

Boolean operators are used in programming. It would be hard for me to explain exactly how they are used in programming without giving you a programming course, but I can tell you basically what they do. The main boolean operators are AND, OR, NOT, and XOR (exclusive or). So: * (true AND true) makes true * (true AND false) makes false * (false AND true) makes false * (false AND false) makes false * (true OR true) makes true * (true OR false) makes true * (false OR true) makes true * (false OR false) makes false * (NOT true) make false * (NOT false) makes true XOR is the same as OR except that it only allows one or the other to be true; not both: * '''(true XOR true) makes false''' * (true OR false) makes true * (false OR true) makes true * (false OR false) makes false Boolean operators can be mixed together like this: NOT (true XOR (false AND true)) makes false In programming, you often use symbols to represent these instead of writing out the words. OR is , not is !, and AND is &&. -DJ Craig They are often used by search engines. If you put in "Bob" AND "Smith" you would get results that have both Bob and Smith in them (say 150 results). If you put in "Bob" OR "Smith" you would get any result with Bob or Smith (say 3000 results). If you put in "Bob" NOT "Smith" you would get Bob Jones, but not Bob Smith. Not all search engines use these. And some use other terms for them.

Answer 2

Boolean operators:
=
!=
>
<
>=
<=

They are used in If/Then/Else statements mainly, to compare two things to each other and return whether it worked or not.

Answer 3

I have an expression I use all the time: "Life is a never-ending series of binary decisions." While that might be debatable about life in general, it certainly is not if you limit the context of "life" to the world of computers. When all the software code is boiled down to its most fundamental components, it's all ones and zeros. A microprocessor or some form of digital, combinational circuitry is going to behave a certain way if it encounters, on one of its input pins, a digital one, usually (but not necessarily) a high voltage, and another way altogether if it encounters a digital zero, usually (again, not necessarily) a low voltage. If you have enough of those digital inputs, all having ones or zeros on them, you have a lot of combinations of ones and zeros, and each combination will cause the circuitry to respond in a different way. The concept in the paragraph above can be made clear with a simple and familiar example: the two-way light switch. For those who are wondering, two-way light switches work as a team. Two switches, usually at opposite ends of a room or the top and bottom of a staircase, operate one light. To turn the light on, both two-way switches must be in the same position; they both must either be flipped in the up position, or they must both be in the down position. If the two switches are in different positions, the light is off. Let's assign a value of binary one to a switch in the up position and value of binary zero to a switch in the down position. We will also assign a value of binary one to the light when it is on, and binary zero when it is off. The following table -- called a truth table -- illustrates the behavior of the light and two-way switches. Let us label the switches A and B and the light L. A B L (Light) 0 0 1 (ON) 0 1 0 (OFF) 1 0 0 (OFF) 1 1 1 (ON) We can write a Boolean expression that represents the data in the table above: A'B' + AB = L, where A' and B' (pronounced A-not and B-not) are the zero states of switches A and B, and A and B are the one states of the switches. In other words, when both switches are in their zero states (A'B'), the switch is on, and when both switches are in their one states (AB), the switch is on. Stated yet another way, if A-not and B-not or A and B, then L. Now what do the two-way switches have to do with computer systems? Well, all computers use the same type of logic to do their thing, but they process way more than just two variables, A and B. They process hundreds and even thousands of different variables. If there are n variables, there are 2n different states those variables could represent. Let's look at a system that is far more complex than the light controlled by two-way switches but is by no means a complex system. Imagine a controller for an elevator that has to service three floors. The elevator will have at least three buttons, one for each floor, and others for opening and closing the doors and stopping the car in case of an emergency. The first and third floors will have one call button, and the second floor will have two (up and down). Sensors on every floor would send a signals -- a binary ones or binary zeros -- to the controller to tell it where the car is. Even the direction of the elevator is a sort of variable, because if the elevator is going down from the third floor, it makes no sense to stop for a passenger on the second floor who wishes to go up. All those variables can be displayed in truth-table format, and Boolean expressions can be written to represent the tables. Instead of just two variables that determine whether a light is on or off, the myriad states of the elevator variables would determine whether the elevator car starts in motion or stays put, whether it goes up or down, and whether it stops at a floor or bypasses it. And all those states could be reduced to a series of Boolean expressions.

Answer 4

The standard Boolean operators are AND, OR and NOT.

From these, Boolean algebra derives 3 more "derived" operators--material implication, exclusive or, and equivalence.

They are used to evaluate a Boolean expression. These expressions all evaluate to either TRUE or FALSE.

Answer 5

In programming. True/false can come in handy when asking questions like; "What is the state of this?"