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Javascript has a native method  sort  that allows sorting arrays. Doing a simple  array.sort()  will treat each array entry as a string and sort it alphabetically. Also you can provide your  own custom sorting  function. [ 'Shanghai' , 'New York' , 'Mumbai' , 'Buenos Aires' ] . sort () ; // ["Buenos Aires", "Mumbai", "New York", "Shanghai"] But when you try order an array of non ASCII characters like this  ['é', 'a', 'ú', 'c'] , you will obtain a strange result  ['c', 'e', 'á', 'ú'] . That happens because sort works only with the English language. See the next example: // Spanish [ 'único' , 'árbol' , 'cosas' , 'fútbol' ] . sort () ; // ["cosas", "fútbol", "árbol", "único"] // bad order // German [ 'Woche' , 'wöchentlich' , 'wäre' , 'Wann...

How can we improve and make a more efficient nested  if  statement in javascript? if (color) { if (color === 'black' ) { printBlackBackground () ; } else if (color === 'red' ) { printRedBackground () ; } else if (color === 'blue' ) { printBlueBackground () ; } else if (color === 'green' ) { printGreenBackground () ; } else { printYellowBackground () ; } } One way to improve the nested  if  statement would be using the  switch  statement. Although it is less verbose and is more ordered, it’s not recommended to use it because it’s so difficult to debug errors. Here’s  why . switch (color) { case 'black' : printBlackBackground () ; break ; case 'red' : printRedBackground () ; break ; case 'blue' : printBlueBackground () ; break ; case 'green' : printGr...

Inserting an item into an existing array Inserting an item into an existing array is a daily common task. You can add elements to the end of an array using push, to the beginning using unshift, or to the middle using splice. Those are known methods, but it doesn’t mean there isn’t a more performant way. Here we go: Adding an element at the end Adding an element at the end of the array is easy with push(), but it can be done in different ways. var arr = [ 1 , 2 , 3 , 4 , 5 ] ; var arr2 = [] ; arr . push ( 6 ) ; arr[arr . length ] = 6 ; arr2 = arr . concat ([ 6 ]) ; Both first methods modify the original array. Don’t believe me? Check the  jsperf Performance on mobile : Android (v4.2.2) arr.push(6);  and  arr[arr.length] = 6;  have the same performance // 3 319 694 ops/sec arr2 = arr.concat([6]);  50.61 % slower than the other two methods Chrome Mobile (v33.0.0) arr[arr.length] = 6;  // 6 125 975 ops/sec arr.push(6);  66.74 % slower arr2 =...

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Asynchronicity in Programming Languages Computers are asynchronous by design. Asynchronous means that things can happen independently of the main program flow. In the current consumer computers, every program runs for a specific time slot and then it stops its execution to let another program continue their execution. This thing runs in a cycle so fast that it's impossible to notice. We think our computers run many programs simultaneously, but this is an illusion (except on multiprocessor machines). Programs internally use  interrupts , a signal that's emitted to the processor to gain the attention of the system. I won't go into the internals of this, but just keep in mind that it's normal for programs to be asynchronous and halt their execution until they need attention, allowing the computer to execute other things in the meantime. When a program is waiting for a response from the network, it cannot halt the processor until the request finishes. Normally, programming ...