boolean usage in java

Boolean is a type that represents true and false values ​​in Java, and the value is true or false. Its usage includes: conditional judgment, logical operation and Boolean return value of method. The declaration usage method is boolean variable name = true/false. Use == or != for comparison. Logical operators include AND, OR, and NOT. Example: Check if a number is even and display a message based on the result.

Usage of boolean type in Java

Boolean is a data type in Java that represents true and false values. It has only two possible values: true or false.

Usage

The boolean type is mainly used in the following situations:

• Conditional judgment: Used in Conditions are judged in control structures such as if, while, and for.
• Logical operations: Used to perform logical operations such as AND (&&), OR (||), and NOT (!). These operators combine multiple boolean values ​​to form a new boolean value.
• Boolean return value of the method: Some methods return a boolean value indicating the result of the operation. For example, the equals() method of the String class compares strings for equality and returns true or false.

Declaration

To declare a boolean variable, you can use the boolean keyword, followed by the variable name:

boolean isTrue = true;

Assignment

Boolean variables can be assigned values ​​through the assignment operator (=):

isTrue = false;

Comparison

Boolean values ​​can be assigned through the equality operator (== ) or the inequality operator (!=) for comparison:

if (isTrue == true) {
    // 执行代码块
}

Logical operations

Java provides the following logical operators:

• AND (&&): When both operands are true, return true; otherwise, return false.
• OR (||): When one of the operands is true, return true; otherwise, return false.
• NOT (!): Invert the Boolean value of the operand.

Application Example

The following is a practical application example of the boolean type:

// 检查一个数字是否为偶数
boolean isEven = (number % 2 == 0);

// 根据布尔值显示消息
if (isEven) {
    System.out.println("该数字是偶数。");
} else {
    System.out.println("该数字是奇数。");
}

The above is the detailed content of boolean usage in java. For more information, please follow other related articles on the PHP Chinese website!