Why are the hrefs operated by JS all javascript:void(0);_Basic knowledge

1. I am a noob

The second half of the year will be much more impetuous, so I have to study hard and say goodbye to the newbies. I decisively bought a few books:

Among them, the first thing I read was "Javascript Pattern" - a book that many people think is terrible. ...500 words of comments and reflections are omitted... When I saw the end of Chapter 2, I once again saw the point of "avoid using void in JS", which aroused my troubles as a novice. A long-standing question: "Since void is not recommended in JS, why do the JS operations of href on the homepages of Sina Weibo, Taobao and others all use javascript:void(0);?"

Screenshot as proof!

Why? Why? Are you watching? Are you watching?

2. Xiaobai’s doubts

No matter how hard you tear it up, you can’t ride on my sister! You can’t tear me off if you want to ride on my sister!

Every time I see void, I remember the nightmare I had many years ago when I first came into contact with programming language C. The only subject I failed in college was C language. It reminds me of that dry woman every time. lecturer. A good and honest student like me, a good classmate who has never been to an Internet cafe before college, does not first elaborate on what the program is and what it is used for. At the beginning, he talks about variables, statements, and XXX, facing the black background every day. Knock on a, b, c with strange things. It feels like being pushed down to the bottom of a river by an older child when you were a child, choking on the water. The clouds are in the fog, and the water is in the soil. I remembered a story I read when I was a child. A young man who went to school in a rural area was lucky enough to go to the UK as an exchange student to study and live in an ordinary person's home (which was naturally very welcoming). However, within a few days, the young man was kicked out - -The reason is: You don’t even lift the toilet seat when you pee, but there is a lady at home. It’s so disrespectful! In fact, it was in this house that this young man saw a toilet for the first time. He had no idea what the toilet seat was for. He had to lift it up when he peeed!

Is it a habit or a norm, I’m confused! I guess the so-called javascript:void(0) ethos is brought about by people with C and C backgrounds in programming, which can be traced back to 10 years ago...

I happened to have my QQ mailbox open, so I looked at its href value, which was javascript:;:

This can prove that void(0) is indeed redundant and useless, so why do so many websites use this? I have to type 7 extra characters every time. What kind of trouble is this? Could it be that the performance is calculated based on the amount of HTML code!

No matter how hard you tear it up, you can’t ride on my sister! You can’t tear me off if you want to ride on my sister!

Then, I have further questions: The semicolon at the end of the statement in JavaScript can be omitted by default, so why use javascript:; instead of javascript:?

Is it a habit or a norm, I’m confused!

Coders who are obsessive about code, just write an extra semicolon for no reason. The holy spirit of the World Cup has been tarnished. How can you endure it? This is not a lot of statements. If you don’t write a semicolon, unexpected situations may occur!

For people like me who are so lazy that my hands cramp up and I feel uncomfortable writing even one more character, I just can’t think about it!

Maybe it’s just because I’m a novice and I don’t understand the world of Ba Shen.

3. I am a noob

I have been using href="javascript:" for many years, but I have always used it with trepidation because others are href="javascript:void(0);". Is it because there are any potential problems with href="javascript:"? For example, does it affect performance? Or make people unable to recognize the toilet seat?

Please give me some advice and comments!

Let’s make a simple summary:

Please refer to the description of void in the link below:

http://www.jb51.net/w3school/js/pro_js_operators_unary.htm

For the above question, borrow the code from the link:

<a onclick="fn()">Does not appear as a link, because there's no href</a> 
<a href="javascript:void(0)" onclick="fn()">fn is called</a> 
<a href="javascript:undefined" onclick="fn()">fn is called</a> 
<a href="javascript:" onclick="fn()">fn is called too!</a> 

The above three are equivalent.

In addition, here is a netizen’s explanation of javascript:; and javascript:void(0);

You can often see code like this when looking at JavaScript scripts:
〈a href="javascript:doTest2();void(0);"〉here〈/a〉
But what exactly does void(0) here mean?
void is an operator in JavaScript that specifies to evaluate an expression but does not return a value.

void operator usage format is as follows:
1. javascript:void (expression)
2. javascript:void expression

expression is a JavaScript-standard expression to be evaluated. The parentheses outside the expression are optional, but it is a good practice to write them.

You can specify a hyperlink using the void operator. The expression is evaluated but nothing is loaded into the current document.

The following code creates a hyperlink that does nothing when the user clicks on it. When the user clicks the link, void(0) evaluates to 0, but has no effect on JavaScript.

The difference between void and #

#Contains a location information. The default anchor point is #top, which is the top of the web page, and javascript:void(0) only represents a dead link.

This is why sometimes the page is very long and the browsing link is clearly # but it jumps to the top of the page, but javascript:void(0) is not the case, so it is best to use void(0) when calling the script.