SEARCH KEYWORD -- Comparison
Can a == true && a == false be true in JavaScript?
JavaScript is a weak typed language and it has a loose comparison feature where two objects/values of different type can be compared using == operator. This provides developers great flexibility and confusion at the same time. Before understanding how == works in JavaScript, can you first answer the question in the post title? Can a == true && a == false be true in JavaScript? Normally, we would think that this expression will always return false since a can be either true or ...
JAVASCRIPT,COMPARISON,INTERVIEW QUESTION,== 2018-03-25 03:39:43
String intern in Java
In Java, == is used to compare whether two objects have the same memory location, equals() is usually used to compare whether two objects have the same time and the same state. When comparing two strings, normally we just want to know whether they have same content, so we can choose equals(). But since String comparison is so frequently needed, Java has worked on the String class to make == workable when comparing two String literals. The String class maintains a pool of emp...
Will nil == nil be true in GoLang
There is some interview question may ask whether nil == nil be true in GoLang. Wil it be true. false or compilation error? To know the answer, some knowledge about nil in GoLang needs to be explained first. nil definition According to Go's official documentation, the definition of nil is // nil is a predeclared identifier representing the zero value for a // pointer, channel, func, interface, map, or slice type. var nil Type // Type must be a pointer, channel, func, interface, map, or slice type...
GOLANG,NIL,NIL EXPLANATION 2021-08-08 02:54:15
<=> operator in MySQL
Have you ever seen "<=>" in a SQL query while using MySQL? Does it mean less and equals to and greater than? Actually if you consider it as the union of <= and =>, great, you are close to it. This is one form of equal operator in MySQL, it has the similar meaning to the = operator with some subtle difference. According to MySQL documentation, <=> is NULL-safe equal. This operator performs an equality comparison like the = operator, but returns 1 rather than NULL if both operand...
C++, Ruby and CoffeeScript complexity comparison
There are many programming languages around the world, they all designed to help programmer solve some problems, finish some tasks. These languages are often divided into different types, there are structural, object-oriented, functional, scripting languages etc. Some are easy to pick up such as Java, while some are thought to be difficult to learn such as C++. So how do we understand complexities of different programming languages?Many people agree that C++ is very complex languages, it has poi...
Complexity, languages, C++,Ruby,CoffeeScript 2012-06-12 04:46:01
What will the value of Integer.valueOf(127) == Integer.valueOf(127) be in Java?
Do you really understand how Java does the integer comparison? OK, ignore the statements in the post title. What we are interested in is another set of comparison statements. Let's first see below code snippet. public class IntegerComparison { public static void main(String[] args) { Integer a = 127, b = 127; Integer c = 128, d = 128; System.out.println(a == b); System.out.println(c == d); } } What do you think the output will be? Are they both displaying true? You will find out t...
Use downcase! with caution in Ruby
Ruby provides ! to change state of some object in place. Hence if you see some functions have ! appended, it means the state of the caller of the function is expected to be changed. This is a very interesting Ruby feature. But sometimes one should be cautious when using this kind of functions because you would get unexpected behavior if using improperly. Let's take an example of String#downcase!. According to the documentation. Downcases the contents of str, returning nil if...
RUBY,EXCLAMATION MARK,DOWNCASE 2017-02-10 06:34:44
Arrays.equals() vs MessageDigest.isEqual()
Both Arrays.equals() and MessageDigest.isEqual() are used to compare the equality of two arrays. They can be interchangeably in many cases. However, they do have some differences which lead to different use cases in real applications. One difference is that the arrays passed to MessageDigest.isEqual() cannot be null while it's ok for Arrays.equals(). The one major difference between these two methods is that Arrays.equals() is not time-constant while MessageDigest.isEqual() is time-constant. Thi...
Arrays.equal(),MessageDigest.isEqual(),Java,Security 2015-05-14 22:03:29
Function Pointers in C are Underrated
The function pointer in C is, in my opinion, one of the most ignored gems of the language. It’s the kind of feature you rarely need, and then suddenly, one day, you find yourself in dire need of it, as evidenced by the real-life use-case below. If you don’t know what a function pointer is in the first place, here’s the meat of it: it gives you the ability to pass a function around like a normal variable. If you know Python / Ruby / Lisp, you might know it by the name...
Can a === 1 && a === 2 && a === 3 be true in JavaScript?
Lots of you may be aware that there is famous interview question which asks whether a == 1 && a == 2 && a == 3 can be true in JavaScript. And the answer to this question is YES. The reason is that == will do a non-strict comparison which will evaluate a to a number and this provides the possibility of dynamically return the value when every time a is accessed. Have you ever wondered whether a === 1 && a === 2 && a === 3 can be true? At first glance, it seems this ...
JAVASCRIPT,===,STRICT COMPARISON 2018-04-06 12:17:29
RECENT
- Tips for Socializing With Friends During College
- Proximity Cards Do More Than Just Open Doors
- How to choose quality painted auto parts
- Oval engagement rings from MoonOcean: Elegance of form and individual approach
- Hologres vs AWS Redshift
- GoLand connect to Hologres
- A journey to investigate a goroutine leakage case
- Understanding Slice Behavior in Go
- Breaking Barriers: How 3D Printing is Democratizing Product Development
- The Power of Efficiency: 10 Practical Energy-Saving Tips for Tech Startups
- more>>