JavaScript

Will affect the original array.1, Shift (): Deletes the first element of the array, returning the deleted value.2, Unshift (3,4): The parameter is loaded in front of the array, returning the length of the array.3. Pop (): Deletes the last element of

If statement...if (expression) {when and when, execute statement 1EXECUTE Statement 1}If there is only one statement, you can do without {}, such as: if () immediately after the execution of the statement...if (expression) {If an expression is true,

The title is also from the front-end engineer Pen questions. Title Description:Now there is a string that you want to perform n operations on the string, giving two numbers per operation: (P, L) a substring of l that starts with the character from

One, the code Add a new visitor info Remove check from small to large from large to small name: Age: OK serial number name age Operations selection 　　Two3. Summary:Native JavaScript unfamiliar,

To show the mouse's location relative to the browser (as opposed to the screen and the page), we were able to take advantage of the Click event to get an event object about the mouse click. The Clientx and Clienty in this event object include the

1 Regular ExpressionsThe use of a single string to describe, match a series of symbols of a syntactic rule of a string, can be easily understood as a rule to match the conditions of the string.ps:https://regexper.com/to help understand regular

String ObjectThe string object is used to manipulate text (strings).Syntax for creating a String object:New String (s); String (s);ParametersThe parameter s is the value to be stored in the string object or converted to the original string.return

　　Javascript----Practice Eight

1 varBook = {2"Main title": "JavaScript",//There are spaces in the attribute name and must be represented by a string3"Sub-Title": "The Definitive Guide",//there are hyphens in the attribute name and must be represented by a string4' For ': ' All

Let's start with a code primer:varStr='Hello World'; alert (Str.charat (1));//find values by subscript;Alert (Str.indexof ('W',3));//find the string subscript by value; no return-1 is found; there are two parameters (the second parameter can be no,

Although there is inheritance in ES6, it is possible to use the extends keyword. This is not what this is about, but a few ways to implement inheritance before ES6.(i) prototype chainECMAScript the prototype chain as the primary way to implement

SummaryCollected 15 commonly used JavaScript regular expressions, including user name, password strength, integer, number, email address (email), mobile phone number, social Security number, URL address, IPv4 address, hex color, date, QQ number,

1. Disadvantages of ArraysAn array does not always organize the best data structure for the information, for the following reasons. In many programming languages, the length of an array is fixed, so it is very difficult to add new elements when the

　　Javascript----Practice Five

var st1 = "2008-8-1 8:50:01"; var st2 = "2008-8-3 8:50:01"; var time1 = new Date (ST1); //Creation time 1 var tiem2 = new Date (ST2); //Creation time 2 /* * If the time difference is the number of days is 864000000, if the number of

I. Type of errorErrorEvalerrorRangeerrorReferenceerrorSyntaxError syntax errorTypeErrorUrierrorError is a base type, and other error types inherit from the object, so all error types share the same set of properties. This type of error is

One, the difference between the scope Var and the let in Es6.1. var is the keyword that defines global variables in JavaScript2. Let is a keyword that defines a variable in the ES6 syntax but the Let variable is a block-level scope (it can only be

1: Property lengthis to get the length of the stringNote: Chinese, digital, English letters, spaces, are 1 lengthseg:"Happy Camp Oh". Length//8var str = ' abc '. length;//32: Attribute prototypeadds a property or method to an object (String), and

In JavaScript this point has been the front-end Colleague's Heart disease, also is the first choice of the interview questions, now we will summarize the JS in the direction of This. First you need to understand several concepts:1: the global

Problems encountered when making a circular progress bar in pure CSS3, and making a circular progress bar in css3   Recently, on the Development page, you need to create a dynamic circular progress bar. The first thing you think of is to use two