Javascript Course


The array_map(), and array_search() functions are generally known and used in PHP. These functions are useful when working with arrays. JavaScript has similar functions, but with other syntax.

array.map()

The array.map(callback) method returns an array containing all the elements of array after applying the callback function to each one.
- Example:
var arr = [1, 4, 9, 16];

//creates an array with the values from arr, doubled
const arr2 = arr.map((v, i)=>v*2);

console.log(arr2); //[2, 8, 18, 32]

array.indexOf()

The JavaScript array.indexOf(value) method is equivalent to the php array_search(value, array) function, it searches the array for a given value and returns the corresponding index if successful, or -1 if none is found.
- Example:
let arr =['ab', 'cd', 90];
var ixv = arr.indexOf('cd');
if(ixv !=-1) document.write('<p>arr contains the value: cd, with index: '+ixv+'</p>');

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which type of <input> creates a date input control, such as a pop-up calendar?
type="text" type="date" type="button"
<input type="date" name="set_date" value="2012-10-15" />
Which CSS property adds shadow effects to the text of an element?
font-style color text-shadow
h2 {
  text-shadow: 2px 3px 3px #a0a1fe;
}
Click on the function that adds new elements to the end of an array.
pop() shift() push()
var pags = ["lessons", "courses"];
pags.push("download", "tutorials");
alert(pags[2]);            // download
Which function sorts an array by key, in ascending order, maintaining key to data correlations?
asort() ksort() sort()
$lang =[10=>"PHP", 20=>"JavaScript", "site"=>"coursesweb.net");
ksort($lang);
var_export($lang);     // array ("site"=>"coursesweb.net", 10=>"PHP", 20=>"JavaScript")
array_map and array_search in JavaScript

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