[javascript/en] Add several usefull functions to work with arrays

javascript.html.markdown

@@ -180,6 +180,23 @@ myArray.length; // = 4
 // Add/Modify at specific index
 myArray[3] = "Hello";
 
+// Add and remove element from front or back end of an array
+myArray.unshift(3); // Add as the first element
+someVar = myArray.shift(); // Remove first element and return it
+myArray.push(3); // Add as the last element
+someVar = myArray.pop(); // Remove last element and return it
+
+// Join all elements of an array with a string
+var myArray0 = [32,false,"js",12,56,90];
+myArray0.join(";") // = "32;false;js;12;56;90"
+
+// Get subarray of elements from index 1 (include) to 4 (exclude)
+myArray0.slice(1,4); // = [false,"js",12]
+
+// Remove 4 elements starting from index 2, and insert there strings
+// "33","34" and "35"; return removed subarray
+myArray0.splice(2,4,"33","34","35");
+
 // JavaScript's objects are equivalent to "dictionaries" or "maps" in other
 // languages: an unordered collection of key-value pairs.
 var myObj = {key1: "Hello", key2: "World"};