Understanding Boolean
Boolean is a data type that represents truth values, either true or false. It's named after George Boole, a mathematician who developed the principles of Boolean algebra.
Logical Operators
Logical operators are used to combine Boolean values and evaluate the resulting truth value. The three main logical operators are:
- AND (&): Evaluates to true only if both operands are true.
- OR (|): Evaluates to true if either operand is true.
- NOT (!): Reverses the truth value of the operand.
Comparison Operators
Comparison operators are used to compare two values and determine if they are equal, greater than, or less than. The most common comparison operators are:
- ==: Equal to
- !=: Not equal to
- >: Greater than
- >=: Greater than or equal to
- <: Less than
- <=: Less than or equal to
Practical Steps
- Declare a Boolean variable using the
boolean keyword.
- Assign a truth value (true or false) to the variable.
- Use logical operators to combine Boolean values and create more complex expressions.
- Evaluate the truth value of an expression using comparison operators.
Javascript Example
// Declare a Boolean variable
let isTrue = true;
// Use a logical operator
if (isTrue && (2 > 1)) {
// Execute code if both conditions are true
}
// Use a comparison operator
if (100 >= 50) {
// Execute code if the condition is true
}
Summary
- Boolean represents truth values (true/false).
- Logical operators combine Boolean values to evaluate expressions.
- Comparison operators compare values to determine equality or inequality.
- Practical steps involve declaring Boolean variables, assigning values, using operators, and evaluating expressions.