freecodecamp javascript

Freecodecamp's JavaScript basic algorithm challengeHttps://www.freecodecamp.com2016-07-03JavaScript is not very familiar with the knowledge to solve these problems, it is estimated that some algorithms will be very stupid.1. Invert stringsStr.split (""). Reverse (). Join ("");2. Factorial (factorial 0 results need to be 1)function factorialize (num) { var n=1; for (var i=num;i>0;i--) { n*=i;} return N;}I can't think of a way to add temporary

Search and Replace1. Requirements Performs a find and replace on a sentence with a given argument and returns a new sentence. The first parameter is the sentence on which to perform the find and replace. The second argument is the word that will be replaced (the word before it is replaced). The third parameter is used to replace the second argument (the replaced word). Preserves the case of the original word when replaced. For example, if you want to replace the word "bo

Title case a sentence (uppercase in the first letter of the word) Requirements Make sure that the first letter of each word in the string is capitalized, and the remainder is lowercase. Connectors like ' the ' and ' of ' are the same. Ideas Use. Split ("") to separate sentences into an array of words. Use the For loop to separate each word in the array with. Split (") into an array of letters, with the first element in the array capitalized, i.e. the

Diff two Arrays (compare two arrays)1. Requirements Compares two arrays and returns a new array The elements of the array are two of all unique array elements in a given array. In other words, returns the difference of two arrays. 2. Ideas Defines a new array variable that joins the two arrays entered with. Concat () to assign to it Defines a check function that returns all the unique array elements in a given array of two Filter out the eligible elements of a

varHTTP = require (' http ') varurl = require (' URL ')) functionParsetime (time) {return{hour:time.getHours (), Minute:time.getMinutes (), Second:time.getSeconds ()} } functionUnixtime (time) {return{unixtime:time.getTime ()}}varServer = Http.createserver (function(req, res) {varParsedurl = Url.parse (Req.url,true) varTime =NewDate (ParsedUrl.query.iso)varresultif(/^\/api\/parsetime/. Test (Req.url)) result=Parsetime (Time)Else if(/^\/api\/unixtime/. Test

---restore content starts---. Pop () removes the element at the end of the array var removedfrommyarray=myarray.pop () Removes the last element of the MyArray array and assigns it to Removedfrommyarray. Shift removes the first element of the array from Var removedfrommyarray=myarray.shift () and assigns the first elements of the MyArray array to a removedfrommyarray. push () Adds an element at the end of the array. Unshift () Add an element example at the beginning of the array: Myarray.push (["

Map the debrisReturns an array whose contents convert the average elevation of the corresponding element in the original array to its corresponding orbital period.The original array contains the formatted object content, like this {name: ‘name‘, avgAlt: avgAlt} .A formula for calculating orbital periods with orbital heightsA: Half-length axis of the track (m),μ = GMThe value to be evaluated should be the nearest integer, and the orbit is based on the earth.The earth radius is 6367.4447 kilomet

= = = 1) {Permutations.push (Arr.join (")); } else {for (var i = 0;iN; ++i) {generate (n-1); Swap (n% 2 0:i, n-1); }}} generate (Arr.length); Filter out arrays of non-sequential repeats var filtered= Permutations.filter (function (String){return!string.match (regex); }); Return the number of return filtered.length; } Alert (Permalone ("AABFCDF"));Heap ' s algorithm full permutation algorithmpr

Falsy Bouncer (filter array false values) Requirements Deletes all false values in the array. (in JavaScript, false values are,,,, false null 0 "" , undefined and NaN .) ） Ideas Use. Filter () to reject false values in an array Use Boolea to set callback function to encounter true value return Code 1 function bouncer (arr) { 2 // Please write your code here 3 function Res (val)

Return largest Numbers in Arrays (Find out the maximum number of multiple arrays) Requirements The large array contains 4 decimal groups, each of which finds the maximum value in each decimal group, and then concatenates them together to form a new array. Ideas Use the For loop to iterate through the algebraic groups and arr[i] access each element of the array in a way. In the first layer for loop, define the variable temp as the first element of the subar

Arguments Optional 1. Requirements Create a function that calculates the sum of two parameters. If there is only one argument, a function is returned, and the function requests a parameter and then returns the result of the sum. If none of the two parameters is a valid number, the undefined is returned. 2. Ideas Determine the number of input data The number of data is 1, the data type is judged, Type is a number: Assign this data to a, return a fun

Spinal Tap case1. Requirements Converts a string to a spinal case. Spinal case is all-lowercase-words-joined-by-dashes in this form, that is, connecting all lowercase words with hyphens. 2. Ideas Use. Replace () and regular expressions to separate lowercase letters and capitals with a space Again 3. Replace the space with a '-' and finally lowercase.function spinalCase(str) { var regex = /\s+|_+/g; str = str.replace(/([a-z])([A-Z])/g, ‘$1 $2‘); return str.replace(regex,

Sum All Primes 1. Requirements Sum of prime numbers less than or equal to a given number. Only 1 and its own two approximate numbers are called prime numbers. For example, 2 is a prime number, because it can only be divisible by 1 and 2. 1 is not a prime number because it can only be divisible by itself. 2. Ideas To define the mark variable in a loop starting from 3 to no more than NUM, initially true Determines whether I is a prime number in a two-layer cycl

Make a person 1. Requirements Constructs an object using the method given below: Getfirstname (), Getlastname (), Getfullname (), Setfirstname (first), Setlastname (last), and Setfullname (Firstandlast). All methods that have parameters accept only one string parameter. All methods interact with the entity object only. 2. Ideas Based on the relevant links, an object is constructed using the method given in the topic. Constructing objects 3. Codevar Perso

DNA Pairing1. Requirements The DNA Strand lacks a paired base. Based on each base, the matching base is found, and the result is returned as a second array. Base pairs (base pair) is a pair of at and CG that matches the missing base for a given letter. The letters and the letters to which they are paired are inside an array, and then all the arrays are organized and encapsulated into an array. 2. Ideas Use. Split (") to divide the entered letter string into an alph

Where Art Thou1. Requirements Write a function that iterates through an array of objects (the first parameter) and returns an array of all objects that contain matching property-value pairs (the second argument). If the returned array contains property-value pairs for the source object, then each property-value pair of this object must exist in the collection object. 2. Ideas Remove the property of source with Object.keys (source) Use Object.keys () to iterate thro

FreecodecampHttps://www.freecodecamp.com2016-07-03A few days ago in GitHub browsing, accidentally saw a call Freecodecamp open-source project, go into the site after the website feel a bit of Earth green, a bit like a personal build not reliable. But it unexpectedly has an additional public welfare project, is to help non-profit free programming, looked at a bit like really a little. So with the idea of a try to start the inside of the free programmin

Freecodecamp Advanced algorithm address stamp here.Freecodecamp Elementary and intermediate algorithm, basic to a thought can be completed, and advanced algorithm a little trouble, so I will own the solution to write clearly, if there are errors or better solution, welcome message.Validate US Telephone NumbersIf the incoming string is a valid US phone number, it is returned true .In short, the rule of the U.S. number is that the country code (must be

Roman numeral Converter1. Requirements Converts a given number into Roman numerals All returned Roman numerals should be in uppercase form 2. Ideas Array of corresponding Roman numerals for single-digit, 10-bit, hundred, thousand, respectively Use Math.floor () to remove numbers from each bit of the number, and to find the corresponding Roman numerals in the previously defined array. 3. Codefunction convert(num) {var arr1 = [‘‘,‘I‘,‘II‘,‘III‘,‘IV‘,‘V‘,‘VI‘,‘VI

Reverse a string (flip string) Title Requirements: Convert a string to an array Flipping the array order with the reverse method of the array Convert an array to a string Ideas: Use. Split (") to convert a string into an array of single letters Use. Reverse () to invert the array Concatenate array elements into strings using. Join (') The code is as follows: 　　 1 function reversestring (str) { 2 // Please write y