Regular: Rules syntax var a=/expression/input value to include an expression var a1 = new RegExp (' expression ') Retrieving---expressions. Test (entered value) returns a Boolean type Regular symbols (regular for multiple symbols, with ()) ^---Enter a value that is the first digit of the character after the symbol $---End with a character before the symbol + characters before the----symbol can appear multiple * characters before---symbol can occur any number of times ? ---Symbols can occur 0 or 1 times before        {N}---Symbol must be available n times before character, but to start, end {n,}---symbol can appear at least n times before the character, but to start, end       {N,M}--the symbol pre-character can appear at least n times up to M times; but to add a start, end . ---match any character except/r/n | ---or (a|b) $ A end b all lines [a-z]-- -Match all (lowercase) A to Z characters---var a =/[a-z]/; [^a-z]--matches all not (lowercase) A to Z characters---var a =/[^a-z]/; Capital Letter [a-z] Capital-lowercase [a-z] /^[a-z][0-9][a-z]&/; ---this type of alphanumeric notation can only be written in one numbers [0-9] = = =/d /D means non-numeric [any character] Match a of any character inside Form Validation use JS, regular to fill in the value of the Judgment dom Models html Dom:html's standard programming interface----defines the objects and properties of all HTML elements and how to access them dom is the standard for how to get, modify, delete, and add HTML elements dom Node: &NBsp; Gets the element node: 1.document.getelementbyid, etc. return to node object ADD: Create new element createelement CreateAttribute (Create Attribute) createTextNode (create text) The newly added node is appended to the Touch node (node: label, text) parent node. appendchild (child nodes) new Attribute node appended to the label where the attribute needs to be added. Setattributenode (properties created) Property Assignment: Label name. SetAttribute (attribute, value) insertbefore (the Label object to insert, before which label you want to insert) need to use body because all are inserted in body Replace: ReplaceChild (the element you want to replace, the element that needs to be replaced) replication 1. Latent copy the element that needs to be copied. CloneNode (false) to append to the element you want to add in the end Copy labels only 2. Deep copy elements that need to be copied. CloneNode (true) Finally append to the element you want to add Copy tags and contents Delete: Delete is determined by parent element parent element. RemoveChild (elements that need to be removed) Modify: Modify CSS styles such as HTML content innertext document.getElementById (). Style.color DOM Summary: Add, delete----is the parent node of the child node operation, (add sometimes) need reference Modify, Get----As long as you know the element attribute (signature, class value, id) I can get all of your information and can make changes
JS regex, form validation, Dom model
