I used to think that script can be placed anywhere in HTML. I corrected my misconception when I made a request today - the location of script is not random.
First of all, I want to implement a select tag with two options: yes and no. However, during initialization, the select tag is required to select a null value by default, so I added a method to let it change the null value when clicking. Delete:
<!DOCTYPE html>
<html>
<head>
<script src="jquery/jquery-1.11.1.min.js"></script>
</head>
<script>
$('#checkcash').click(function () {
if ($('#checkcash').val() == '0') {
$("#checkcash option[value='0']").remove();
}
});
$("#alert").click(function(){
alert("1123");
})
</script>
<body>
是否已提现 <select id="checkcash" style="width: 181px">
<option selected="selected" value="0"></option>
<option value="1">是</option>
<option value="2">否</option>
</select>
<input type='button' id='alert' value="anwo">
</body>
</html>But this does not achieve the desired effect. At first I thought it was a jquery syntax error and I kept checking and correcting it online, but it didn’t work. Then I suddenly thought about it. I should have put the script at the back and tried it. It turned out to be ok. Then I suddenly realized that it was not like this.
Later I checked the reason is because the html file is executed in a top-down manner, but the order of the imported css and javascript is different. When the css is introduced for execution and loading, the program The execution continues, and when the <script> script is executed, the thread is interrupted, and the program continues execution only after the execution of the script is completed. Therefore, the script is generally placed after the body to avoid delayed blocking due to long execution of the script. To achieve the effects of some pages, some js scripts need to be dynamically loaded in advance, so these scripts should be placed before <body>. <span style="color: #ff0000;">Secondly, the js that needs to access the dom element cannot be placed before the body, because the dom has not yet started to be generated, so the js that accesses the dom element before the body will error or be invalid. <span style="color: #000000;">It is because of this that I added methods to the dom before it was generated, which led to this. </script>
# I really should study a lot of things and think so, but I didn’t delve into it. Keep working hard in the future!
ps: In fact, there is another way, which is to use jquery's initialization page method to add the click event added to the label above to $(function (){}) is also possible. The principle is the same as above. This method is executed after the page is loaded, so it can be placed anywhere!
The above is the detailed content of Where should be placed in html?. For more information, please follow other related articles on the PHP Chinese website!
From Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AMHTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.
Understanding HTML, CSS, and JavaScript: A Beginner's GuideApr 12, 2025 am 12:02 AMWebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.
The Role of HTML: Structuring Web ContentApr 11, 2025 am 12:12 AMThe role of HTML is to define the structure and content of a web page through tags and attributes. 1. HTML organizes content through tags such as , making it easy to read and understand. 2. Use semantic tags such as, etc. to enhance accessibility and SEO. 3. Optimizing HTML code can improve web page loading speed and user experience.
HTML and Code: A Closer Look at the TerminologyApr 10, 2025 am 09:28 AMHTMLisaspecifictypeofcodefocusedonstructuringwebcontent,while"code"broadlyincludeslanguageslikeJavaScriptandPythonforfunctionality.1)HTMLdefineswebpagestructureusingtags.2)"Code"encompassesawiderrangeoflanguagesforlogicandinteract
HTML, CSS, and JavaScript: Essential Tools for Web DevelopersApr 09, 2025 am 12:12 AMHTML, CSS and JavaScript are the three pillars of web development. 1. HTML defines the web page structure and uses tags such as, etc. 2. CSS controls the web page style, using selectors and attributes such as color, font-size, etc. 3. JavaScript realizes dynamic effects and interaction, through event monitoring and DOM operations.
The Roles of HTML, CSS, and JavaScript: Core ResponsibilitiesApr 08, 2025 pm 07:05 PMHTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.
Is HTML easy to learn for beginners?Apr 07, 2025 am 12:11 AMHTML is suitable for beginners because it is simple and easy to learn and can quickly see results. 1) The learning curve of HTML is smooth and easy to get started. 2) Just master the basic tags to start creating web pages. 3) High flexibility and can be used in combination with CSS and JavaScript. 4) Rich learning resources and modern tools support the learning process.
What is an example of a starting tag in HTML?Apr 06, 2025 am 12:04 AMAnexampleofastartingtaginHTMLis,whichbeginsaparagraph.StartingtagsareessentialinHTMLastheyinitiateelements,definetheirtypes,andarecrucialforstructuringwebpagesandconstructingtheDOM.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
Hot Tools
SublimeText3 Chinese version
Chinese version, very easy to use
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
Dreamweaver Mac version
Visual web development tools
SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
