Detailed explanation of common operations on JavaScriptDOM elements [add, delete, modify, etc.]
The examples in this article describe common operations on Javascript DOM elements. Share it with everyone for your reference, the details are as follows: DOM Concept DOM (Document Object Model): Document Object Model. Can be viewed through the Elements tab of the developer tools You can also observe that the entire document has a series of nodes through the Sources tab of the developer tools The entire document is a tree composed of a series of node objects. Nodes include element nodes (1), attribute nodes (2), and text nodes (3) (1..2..3..represent node types)_ var th1= document.getElementById(“th1”); alert(th1.nodeType); alert(th1.nodeName); alert(th1.nodeValue); th1 represents an element node (nodeType=1), nodeName is the label name (th), and nodeValue=null of the element node. var attr1=th1.getAttributeNode(“name”); alert(attr1.nodeType); alert(attr1.nodeName); alert(attr1.nodeValue); The getAttributeNode method is to get the attribute node of the element. At this time, the output node type is the attribute node (2), the node name is the attribute name (name), and the node value is the attribute value (sex) var txtl = th1.firstChild; alert(txtl.nodeType); alert(txtl.nodeName); alert(txtl.nodeValue) txt1 is a text node (3), the node name is fixed to #text, and the node value is the text content. Get element (1)getElementByid Get the element based on its…
Access, create, modify, and delete DOM nodes in JavaScript
DOM DOM is the abbreviation of Document object Model. The document object model is a document that expresses XML or HTML in the form of tree nodes. Using DOM methods and properties, you can access, modify, delete any element on the page, and you can also add an element. DOM is a language-independent API that can be implemented in any language, including Javascript Take a look at one of the texts below. first paragraph second paragraph final Let’s take a look at the second paragraph second paragraph You can see that this is a p tag. It is included in the body tag. So body is the parent node of p, and p is the child node. The first and third paragraphs are also child nodes of the body. They are all sibling nodes of the second paragraph. This em tag is a child node of the second segment p. Therefore p is its parent node. The parent-child node relationship can depict a tree-like relationship. So it’s called DOM tree. Core DOM and HTML DOM We already know that DOM can depict HTML and XML documents. In fact, an HTML document is an XML document, but more standardized. Therefore, as…
Java uses object-oriented programming thinking to write a library management system: add, query, modify, delete, exit, how to write?
Java uses object-oriented programming thinking to write a library management system: add, query, modify, delete, exit, how to write? pac How to add, delete, modify and check books using java multi-layer list? import java.util.ArrayList;import java.util.List;/*** Test class** @author time is flowing**/public class Test { /*** This attribute is used to imitate Study room*/private List<List> room = new ArrayList<List>(); /*** Add a bookshelf to the study room** @return The index of the newly added bookshelf*/public int addBookShelf() {room.add(new ArrayList());return room.size() – 1;} /*** Add a book to the bookshelf** @param bookShelfIndex bookshelf index* @param book book. Here, a string is used to represent a book. You can also create a separate book class if you wish* @return The index of the newly added book*/public int addBook(int bookShelfIndex, String book) {List shelf = room .get(bookShelfIndex);shelf.add(book);return shelf.size() – 1;} // I won’t write about updating the bookshelf. /*** Update a book on the bookshelf** @param bookShelfIndex bookshelf index* @param bookIndex old book index* @param newBook new book*/public void setBook(int bookShelfIndex, int bookIndex, String newBook ) {List shelf = room.get(bookShelfIndex);shelf.set(bookIndex, newBook);} /*** Remove a bookshelf** @param bookShelfIndex bookshelf index* @return the number of remaining bookshelves*/ public int removeBookShelf(int bookShelfIndex) {room.remove(bookShelfIndex);return room.size();} /*** Remove a…
I don’t know how to add, delete, modify, and sort javascript tables (first time writing a blog, please share)
I have been learning JS for almost a month. The blogger himself went to a training program and is about to take the exam. I will take tutoring lessons for what I have learned. Post what I wrote tonight. . . Someone can look at my level and see how I can sort things~~ Name: Age: AddConfirm changes Introduce color changing switchTurn off color changing switch p> Search th>Name
A complete collection of Javascript operation select controls (add, modify, delete, select, clear, determine existence, etc.)
1 Determine whether there is an Item with Value=”paraValue” in the select option 2. Add an Item to the select option 3 Delete an Item from the select option 4Delete the selected item in select 5 Modify the text of value=”paraValue” in the select option to “paraText” 6Set the first Item with text=”paraText” in the select to be selected 7 Set the Item with value=”paraValue” in select to be selected 8 Get the value of the currently selected item of select 9 Get the text of the currently selected item of select 10 Get the Index of the currently selected item of select 11Clear selected items js code // 1. Determine whether there is an Item with Value=”paraValue” in the select option function jsSelectIsExitItem(objSelect, objItemValue) { var isExit = false; for (var i = 0; i <objSelect.options.length; i++) { if (objSelect.options[i].value == objItemValue) { isExit = true; break; } return isExit; } // 2. Add an Item to the select option function jsAddItemToSelect(objSelect, objItemText, objItemValue) { //Determine whether it exists if (jsSelectIsExitItem(objSelect, objItemValue)) { alert(“The Value of this Item already exists”); } else { var varItem = new Option(objItemText, objItemValue); objSelect.options.add(varItem); alert(“Joined successfully”); } } // 3. Delete an…
Development Notes: Java Small Project (Login, Add, Delete, Modify, Check, Page Search)
Preface: This article is organized by the editor of Programming Notes# for everyone. It mainly introduces the knowledge related to Java-small projects (login, add, delete, modify, check, and page search). I hope it will be of certain reference value to you. Java–Small project (login, addition, deletion, modification, paging, Search) Blog description The information involved in the article comes from the Internet and personal summary, and is intended to be a summary of personal learning and experience , if there is any infringement, please contact me to delete it, thank you! Concept Technical Selection Servlet, JSP, mysql, JDBCTempleat, Duird, BeanUtilS, tomcat Function introduction Login function, list display, data addition, data editing, data deletion, batch deletion, paging display, keyword search Create JavaWeb project Import dependencies Add page file Database create database little; — Create databaseuse little; — Use databasecreate table user( — Create table id int primary key auto_increment, name varchar(20) not null, gender varchar(5), age int, address varchar(32), qq varchar(20), email varchar(50, username varchar(32), password varchar(32),); List display Idea First we need a set of list data, then we need a corresponding servlet, through our three-tier architecture, use service as the same interface, and then call the dao layer to use…
Javascript operation select control encyclopedia (add, modify, delete, select, clear, determine existence, etc.)
Collect it 1. Determine whether there is an Item with Value=”paraValue” in the select option2. Add an Item to the select option3. Delete an Item from the select option4. Delete it from the select option Selected item5. Modify the text of value=”paraValue” in the select option to “paraText”6. Set the first Item with text=”paraText” in the select to be selected7. Set select The Item with value=”paraValue” is selected8. Get the value of the currently selected item of select9. Get the text of the currently selected item of select10. Get the Index of the currently selected item of select11. Clear selected items //js code// 1. Determine whether there is an Item with Value=”paraValue” in the select option function jsSelectIsExitItem(objSelect, objItemValue) { var isExit = false; for (var i = 0; i <objSelect.options.length; i++) { if (objSelect.options[i].value == objItemValue) { isExit = true; break; } } return isExit; } // 2. Add an Item to the select option function jsAddItemToSelect(objSelect, objItemText, objItemValue) { //Determine whether it exists if (jsSelectIsExitItem(objSelect, objItemValue)) { alert(“The Value of this Item already exists”); } else { var varItem = new Option(objItemText, objItemValue); objSelect.options.add(varItem); alert(“Successfully added”); } } / / 3. Delete an Item from the select option…
How to add, modify, and delete IDs with Javascript.
1 test How to add a ‘red’ to the box, or delete the added ‘red’?
javaoracle add, delete, modify, query_Java database operation oracle add, delete, modify, query, general encapsulation based on hashmap
pt1: First install the oracle connection driver Download address：https://pan.baidu.com/s/1jW_ofgU4eJmAn7Y2J5B46A Password：epkz 1 .Import ojdbc6.jar into the project First create a project ， then right-click on the project–>new–>folder;folder name:lib; so that it is in the project Created a folder lib; then imported the ojdbc6.jar package into the folder 2. Right-click the Reference Library package–>build path–>add extend and import the jar package apply and save; p> package Db; import java.sql.*; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.HashMap; import java.util.Map; import org.openqa.selenium.remote.server.handler.DeleteCOOKIE; import bsh.This; import net.sf.json.JSONArray; import net.sf.json.JSONObject; public class OrcTest { String url; String user; String pwd; String sql; Connection connect;//Create a database connection PreparedStatement pre;//Create a precompiled statement object，usually used This instead of Statement ResultSet result; public OrcTest(String url,String user,String pwd){ this.url=url; this.user=user; this.pwd=pwd; try { Class.forName(” oracle.jdbc.driver.OracleDriver”); this.connect=DriverManager.getConnection(this.url, this.user, this.pwd); }catch ( Exception e) { System.out.println(“Failed to connect to data driver”); e.printStackTrace(); } } public void CloseDb(){ try { if(this.pre !=null) { this.pre.close(); System.out.println(“Close things”); } if(this.result !=null) { this.result.close(); System.out.println(“Close the result object”); } if(this.connect !=null) { this.connect.close(); System.out.println(” Close the connection”); } }catch (Exception e) { e.printStackTrace(); } } // exe_select public ArrayList exeselect(String sql) { ArrayList list =new ArrayList(); try { this.pre=this.connect.prepareStatement(sql); this.result = this.pre.executeQuery( ); ResultSetMetaData…
Convert JavaScript to operate select controls (add, modify, delete, select, clear, determine existence, etc.)…
Collect it 1. Determine whether there is an Item of Value=”paraValue” in the select option2. Add an Item to the select option3. From select Delete an Item in the options4. Delete the selected item in the select5. Modify the text of value=”paraValue” in the select option to “paraText”6. Set the text& in the select #61;The first Item of “paraText” is selected7. Set the value in select=The Item of “paraValue” is selected8. Get the value of the currently selected item of select9. Get the text of the currently selected item of select10. Get the Index of the currently selected item of select11. Clear the selected items //js code // 1. Determine whether there is an Item of Value=”paraValue” in the select option function jsSelectIsExitItem(objSelect, objItemValue) { var isExit = false; for (var i = 0; i < objSelect.options.length; i++) { if (objSelect.options[i]. value == objItemValue) { isExit = true; > return isExit; } // 2. Add an Item to the select option function jsAddItemToSelect(objSelect, objItemText, objItemValue) { //Determine whether it exists if (jsSelectIsExitItem(objSelect, objItemValue)) { alert(“The Value of this Item already exists”); } else { var varItem = new Option(objItemText , objItemValue); objSelect.options.add(varItem); alert( “Joined successfully”); } } // 3.…
