javascript string concatenation operator

simpler version that might be just as efficient:String. prototype. times = function (n) {return (new Array (n + 1). join (this );};When you call the Array () constructor with a single numeric argument, it just sets the length of the returned array, and doesn't actually create any elements for the array.I 've only tested these in Firefox. I'm assuming that either is more efficient than anything that involves an actual loop, but I haven't run any benchmarks.ExplanationMy English is so bad that I

In JavaScript, we are often exposed to the 5 more special objects mentioned in the topic--false, 0, empty strings, null, and undefined. These objects are easy to use, so you have to be careful when you use them.Type detectionLet's come down and see what their type is:　　Running the above code, the dialog box that pops up should display true. That is, False is a Boolean type object, 0 is a numeric type object, an empty

In JavaScript, we are often exposed to the 5 more special objects mentioned in the topic-false,0, empty strings ,null , and undefined . These objects are easy to use, so you have to be careful when you use them.Type detectionLet's come down and see what their type is: Running the above code, the dialog box that pops up should display true. That is,false is a Boolean type object, 0 is a numeric type object, an empty

JavaScript Concat Method The Concat method joins two or more strings with the following syntax: Copy Code code as follows: Str_object.concat (str1, str2, ...) Str_object is the first string (object) that needs to be connected, str1 is the second string that needs to be connected, str2 is the third string

When we write the front-end JS, many strings are often spliced through "+" and then mounted to a DOM element. However, I will not compare the effect of using "+" to splice strings in different browsers. There are many such comparisons on the Internet. Many cool people say that using the join method of array in JS to concatenate strings is very good. To this end, write a JS class in the project to uniformly process String

One, the string1] ' This is a string ', which is the direct amount of strings, new string (' This is a string '), which is a string object, the string object can be used in the string object with the properties and methods, the di

value, if any, obtained by calculating a string.Eval ("Alert (' Hello World ')")//Popup Hello WorldThe method only accepts the original string as an argument, and if the string parameter is not the original string, the method returns without any change.Therefore, do not pass a String object as a parameter for the eval

In JavaScript, we are often exposed to the 5 more special objects mentioned in the topic--false, 0, empty strings, null, and undefined. These objects are easy to use, so you have to be careful when you use them.Type detectionLet's come down and see what their type is:Running the above code, the dialog box that pops up should display true. That is, False is a Boolean type object, 0 is a numeric type object, an empty

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 origin

JavaScript String Object------is used to process text (strings).To create a String object:/* parameter S is the value to be stored in the string object or converted to the original string.New String (s);String (s);return value:1.

Address: http://www.davidflanagan.com/2009/08/string-multipli.htmlOriginal Author: David FlanaganIn Ruby, the "*" operator uses a string as the left parameter and a number as the right parameter to implement string duplication. For example, the value of "Ruby" * 2 is "rubyruby ". This is useful only in a few places (fo

Original address:http://www.davidflanagan.com/2009/08/string-multipli.htmlOriginal Author: David FlanaganIn Ruby, the "*" operator uses a string as the left argument and a number as the right argument to duplicate the string. For example, the value of "Ruby" * 2 is "Rubyruby". This is only useful in a few places (for e

In order to facilitate debugging, wrote a page is not logged in, Debug mode automatic login function, found that there is a variable i initialized to it to assign a string, but in the use of the time to find it turned false, good magic. After careful examination of the reference, it is found that a judgment condition is less than an equal sign. The JS code is as follows:var ssessionkey = "Test_key";if (Ssessionkey=Undefined | | Ssessionkey = = null) {

Address: http://www.davidflanagan.com/2009/08/string-multipli.htmlOriginal Author: David FlanaganIn Ruby, the "*" operator uses a string as the left parameter and a number as the right parameter to implement string duplication. For example, the value of "Ruby" * 2 is "RubyRuby ". This is useful only in a few places (fo

In general, to understand this code, you need to master the following two functions One is typeof, and one is the ternary operator. Read the above article and then look at the following is better to understand Generally used function code function $ (ID) {return typeof id=== ' string ' document.getElementById (ID): ID;} var Getby = function (ID) {return "

Arrayvar arr= new Array();arr.push(); //在数组尾部添加一个元素，返回新的长度 *原数组发生变化arr.pop(); //删除最后一个元素，返回的是被删除的元素 *原数组发生变化arr.unshift(); //在头部添加一个元素，返回长度 *原数组发生变化arr.shift(); //删除数组第一个元素，返回被删除的元素 *原数组发生变化arr.concat(); //添加元素或数组，返回一个一维数组，可用来合并数组arr.join(); //将数组内的元素用（）内的符号连接起来返回一个字符串arr.reverse(); //颠倒数组中的元素 *原数组发生变化arr.sort(); //将数组元素排序，如果调用该方法时没有使用参数，将按字母顺序对数组中的元素进行排序 *原变arr.slice(x,y); // 返回数组中的一部分，根据下标，前包后不包 arr.splice();//例arr.splice(x)

-memory, and the more cross-memory, the more chaotic. It's better to look at things with a skeptical attitude. Let's give it a try and find out what it looks like. High-quality and assured books or official stuff are good sources. You can see it clearly, and your head is clear. record it and make a memo. Conceptual things are written in books, reducing future misleading. The example is hand-written and verified, and a picture is drawn for later understanding. I. Encapsulation Object definition:T