Answers for "array functions"

common array methods php

$colors = array("blue","green","red");

//delete element in array by value "green"
if (($key = array_search("green", $colors)) !== false) {
    unset($colors[$key]);
}

common array methods php

sizeof($arr) //returns the size of elements in the array
is_array($arr) // returns true if $arr is an array and false otherwise
in_array($var, $arr) // check if $var is in the array $arr
print_r($arr) // prints the complete representation of the array
array_merge($arr1, $arr2) //combines $arr1 and $arr2 into a single array
array_values($arr) //store all the values into a new array without the keys but only the values
array_keys($arr) // returns only the keys inside an array
array_pop($arr) // removes the last element of  the array
array_push($arr, $val) // pushes $val to the end of array
array_shift($arr) // removes the first element in the array $arr
sort($arr) // sorts an array in an ascending order

/*Other sorting methods are:
-asort()
-arsort()
-ksort()
-krsort()
-rsort()
*/

array_map('function_name', $arr) // passes each value in the array inside the fuction and do the operation on the array data
array_flip($arr) //This function interchange the keys and the values of a PHP associative array.
array_reverse($arr) //This function is used to reverse the order of elements
array_rand($arr) //randomly pick an element from the array
array_slice($arr, $offset, $length)//This function is used to create a subset of any array

javascript array

//create an array like so:
var colors = ["red","blue","green"];

//you can loop through an array like this:
for (var i = 0; i < colors.length; i++) {
    console.log(colors[i]);
}

javascript array functions

concat(arr1,[...]) // Joins two or more arrays, and returns a copy of the joined arrays
copyWithin(target,[start],[end]) // Copies array elements within the array, to and from specified positions
entries() // Returns a key/value pair Array Iteration Object
every(function(currentval,[index],[arr]),[thisVal]) // Checks if every element in an array pass a test
fill(val,[start],[end]) // Fill the elements in an array with a static value
filter(function(currentval,[index],[arr]),[thisVal]) //	Creates a new array with every element in an array that pass a test
find(function(currentval,[index],[arr]),[thisVal]) // Returns the value of the first element in an array that pass a test
findIndex(function(currentval,[index],[arr]),[thisVal]) // Returns the index of the first element in an array that pass a test
forEach(function(currentval,[index],[arr]),[thisVal]) // Calls a function for each array element
from(obj,[mapFunc],[thisVal]) // Creates an array from an object
includes(element,[start]) // Check if an array contains the specified element
indexOf(element,[start]) // Search the array for an element and returns its position
isArray(obj) // Checks whether an object is an array
join([seperator]) // Joins all elements of an array into a string
keys() // Returns a Array Iteration Object, containing the keys of the original array
lastIndexOf(element,[start]) // Search the array for an element, starting at the end, and returns its position
map(function(currentval,[index],[arr]),[thisVal]) // Creates a new array with the result of calling a function for each array element
pop() // Removes the last element of an array, and returns that element
push(item1,[...]) // Adds new elements to the end of an array, and returns the new length
reduce(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going left-to-right)
reduceRight(function(total,currentval,[index],[arr]),[initVal]) // Reduce the values of an array to a single value (going right-to-left)
reverse() // Reverses the order of the elements in an array
shift() // Removes the first element of an array, and returns that element
slice([start],[end]) // Selects a part of an array, and returns the new array
some(function(currentval,[index],[arr]),[thisVal]) // Checks if any of the elements in an array pass a test
sort([compareFunc]) // Sorts the elements of an array
splice(index,[quantity],[item1,...]) // Adds/Removes elements from an array
toString() // Converts an array to a string, and returns the result
unshift(item1,...) // Adds new elements to the beginning of an array, and returns the new length
valueOf() // Returns the primitive value of an array

How does array function work?

const printResult = (a, b) => {
    return a + b;
}
console.log(printResult(5, 8));
//Expected output: 13

Array Methods

dogs.toString();                        // convert to string: results "Bulldog,Beagle,Labrador"
dogs.join(" * ");                       // join: "Bulldog * Beagle * Labrador"
dogs.pop();                             // remove last element
dogs.push("Chihuahua");                 // add new element to the end
dogs[dogs.length] = "Chihuahua";        // the same as push
dogs.shift();                           // remove first element
dogs.unshift("Chihuahua");              // add new element to the beginning
delete dogs[0];                         // change element to undefined (not recommended)
dogs.splice(2, 0, "Pug", "Boxer");      // add elements (where, how many to remove, element list)
var animals = dogs.concat(cats,birds);  // join two arrays (dogs followed by cats and birds)
dogs.slice(1,4);                        // elements from [1] to [4-1]
dogs.sort();                            // sort string alphabetically
dogs.reverse();                         // sort string in descending order
x.sort(function(a, b){return a - b});   // numeric sort
x.sort(function(a, b){return b - a});   // numeric descending sort
highest = x[0];                         // first item in sorted array is the lowest (or highest) value
x.sort(function(a, b){return 0.5 - Math.random()});     // random order sort