The difference between & and && in java: 1. When the && operator operates, when the value of the first expression is false, the second expression will not be calculated; while the & operator Then both expressions will be executed regardless of whether the value of the first expression is true. 2. The & operator can be used as a bitwise operator, but the && operator cannot.
The operating environment of this tutorial: windows7 system, java8 version, DELL G3 computer.
In Java, && and & are both logical operators representing "and", which means and. They are all true when the expressions on both sides are true, and the entire operation result is true, otherwise it is false. Next, in the article, we will introduce the differences between the two in detail.
The difference between & and &&
& and && are both logical operators, but && is also called a short-circuit operator. Because when the value of the first expression is false, the second expression will not be evaluated;
and & will execute both expressions regardless of whether the first expression is true. In addition, & can also be used as a bitwise operator. When the expressions on both sides of & are not of Boolean type, & represents a bitwise operation.
&& Operation
int i = 0;
if(i == 3 && ++i > 0 )
{
}
System.out.println("i = " + i);
Copy after login
The result is:
i = 0
Copy after login
Cause: The second expression is not executed
& The result of the operation
int i = 0;
if(i == 3 & ++i > 0 )
{
}
System.out.println("i = " + i);
Copy after login
is:
i = 1
Copy after login
The second expression performs the
expansion Knowledge: Logical operators
Logical operators connect the relational expressions of various operations to form a complex logical expression to determine whether the expression in the program is true and the result of the determination Is true or false.
Logical operators operate on Boolean variables, and their results are also Boolean, as shown in Table 1.
Table 1 Usage, meaning and examples of logical operators
Operator
Usage
Meaning
Explanation
Example
Result
##&&
a&&b
Short circuit and
When ab is all true, the calculation result is true, otherwise it is false.
2>1&&3<4
true
##||
a||b
short circuit or
When ab is all false, the calculation result is false, otherwise it is true.
2<1||3>4
false
##!
!a
logical NOT
When a is true, the value is false, when a is false, the value is true
!(2>4)
true
|
a|b
Logical OR
When ab is all false, the calculation result is false, otherwise it is true
1>2| 3>5
false
&
a&b
logical logic and
ab are both true, The calculation result is true, otherwise it is false
1<2&3<5
true
#|| | Difference: If a is true, b is not calculated (because no matter what the value of b, the result is true)
Note: short-circuit AND (&&) and short-circuit OR (||) Ability to adopt optimized calculation methods to improve efficiency. In actual programming, short-circuit AND and short-circuit OR should be given priority.
Variables or expressions whose results are of boolean type can be combined into logical expressions through logical operators. Logical operators &&, || and ! Perform logical operations according to Table 2.
Table 2 Use logical operators to perform logical operations
其中，第一行语句用于判断 x 的值是否大于 0 且小于或等于 100，只有两个条件同时成立结果才为真（true）。第二行语句用于判断 y 的值是否能被 4 或者 3 整除，只要有一个条件成立，结果就为真（true）。第三行语句先比较 x 和 y，再将比较结果取反，即如果 x 大于 y 成立，则结果为假（false），否则为真（true）。
The above is the detailed content of What is the difference between & and && in java. For more information, please follow other related articles on the PHP Chinese website!
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Java 8 introduces the Stream API, providing a powerful and expressive way to process data collections. However, a common question when using Stream is: How to break or return from a forEach operation?
Traditional loops allow for early interruption or return, but Stream's forEach method does not directly support this method. This article will explain the reasons and explore alternative methods for implementing premature termination in Stream processing systems.
Further reading: Java Stream API improvements
Understand Stream forEach
The forEach method is a terminal operation that performs one operation on each element in the Stream. Its design intention is
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
Capsules are three-dimensional geometric figures, composed of a cylinder and a hemisphere at both ends. The volume of the capsule can be calculated by adding the volume of the cylinder and the volume of the hemisphere at both ends. This tutorial will discuss how to calculate the volume of a given capsule in Java using different methods.
Capsule volume formula
The formula for capsule volume is as follows:
Capsule volume = Cylindrical volume Volume Two hemisphere volume
in,
r: The radius of the hemisphere.
h: The height of the cylinder (excluding the hemisphere).
Example 1
enter
Radius = 5 units
Height = 10 units
Output
Volume = 1570.8 cubic units
explain
Calculate volume using formula:
Volume = π × r2 × h (4
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python each have their own advantages and are suitable for different scenarios. 1.PHP is suitable for web development and provides built-in web servers and rich function libraries. 2. Python is suitable for data science and machine learning, with concise syntax and a powerful standard library. When choosing, it should be decided based on project requirements.
Java is a popular programming language that can be learned by both beginners and experienced developers. This tutorial starts with basic concepts and progresses through advanced topics. After installing the Java Development Kit, you can practice programming by creating a simple "Hello, World!" program. After you understand the code, use the command prompt to compile and run the program, and "Hello, World!" will be output on the console. Learning Java starts your programming journey, and as your mastery deepens, you can create more complex applications.
The reasons why PHP is the preferred technology stack for many websites include its ease of use, strong community support, and widespread use. 1) Easy to learn and use, suitable for beginners. 2) Have a huge developer community and rich resources. 3) Widely used in WordPress, Drupal and other platforms. 4) Integrate tightly with web servers to simplify development deployment.
