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
What attribute makes a radio button or checkbox input selected?
checked="checked" selected="selected" disabled="disabled"
<input type="checkbox" name="a_name" value="value" checked="checked" />
What CSS value scales the background image to the largest size contained within the element?
repeat-x contain linear-gradient
#id {
  background:url("path_to_image.png");
  background-size:contain;
  background-repeat:no-repeat;
}
What operator is used to determine the rest of the division of two numbers?
% * /
var rest8_7 = 8 % 7;
alert(rest8_7);
Indicate the PHP function that rounds a number up to the next highest integer.
floor() ceil() abs()
$nr = ceil(3.5);
echo $nr;        // 4
array_map and array_search in JavaScript

Last accessed pages

  1. Get the Height and Width of web Page and browser Window (2381)
  2. New Form elements and attributes in HTML5 (4901)
  3. Defining classes with Methods that can be chained (913)
  4. Circle and Oval with CSS (6077)
  5. PHP Method Chaining (2625)

Popular pages this month

  1. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (84)
  2. Read Excel file data in PHP - PhpExcelReader (65)
  3. PHP-MySQL free course, online tutorials PHP MySQL code (54)
  4. SHA1 Encrypt data in JavaScript (52)
  5. Create simple Website with PHP (47)