Making Array

For making array it's better to use list literal because it's most popular and simple syntaxis

a = []; //Empty list
b = [1,2,3,4,5]; //List with 5 elements

Work with elements

And so, we have an array 'b' with five numbers and the empty array 'a'.

a[0] = b[2]; //1
delete b[2]; //2
b[3] = 6; //3

1. From array b - [1,2,3,4,5] get element with index 2 (Numeration in arrays starts from 0). Now array a = [2]
2. We delete element with index 2 from array b. Now array b = [0,1,undefined,3,4].
3. We change value of element with index 3 from array b. Now array b = [0,1,undefined,6,4].

Work with slices

Array.slice(start,end) - returns array with elements of Array from start index to end index without element with index end.

a = [0,1,2,3,4,5,6,7];
b = a.slice(2,5); //2,3,4

If start or end is negative number then index of start or end equal (length of array + start or end).

a = [0,1,2,3,4,5,6,7];
b = a.slice(2,-2); //2,3,4,5 because length = 8 and 8 + (-2) = 6

Array.splice(start,number,elem...) - return slice with number of elements from Array from start and it deletes this elements from Array, and it replaces it's by elem

a = [0,1,2,3,4,5,6,7];
b = a.splice(2,3,0,1,0);
print(b); // 2,3,4
print(a); // 0,1,0,1,0,5,6,7

Stack and row

You can use any Array as stack or row for it there are 4 function.

For example:

Foo = [1,2,3,4,5];
Bar = Foo.pop(); //Bar = 5 , Foo = [1,2,3,4]
Foo.unshift(Bar); // Foo = [5,1,2,3,4]

Sorting and reverse

Also Array.sort([predicate]) - If predicate not defined then sort elements in Array in lexicographical order else sort element in Array by results of function predicate that gets two arguements and returns -1 if first argument less than the second or 1 if the second argument is less than the first or 0 if the arguments are equal.

Array.reverse() - reverse elements in Array

arr = [5,3,1,4,2];
arr.sort();
print(arr); //1,2,3,4,5
arr.reverse();
print(arr); //5,4,3,2,1

Concatenate and joining

Array.concat(elem1...) - returns array that containg elements from Array and elem if elem[n] is array then to the array that returns are added all elements from elem[n].

Array.join([separator]) - returns string with all elements and separator before every, if separator not defined then separator = ","

arr1 = [0,1,2,3,4]
arr2 = [5,6,7,8,9]
elem = 10;
arr = arr1.concat(arr2,elem); //0,1,2,3,4,5,6,7,8,9,10
str = arr.join(';'); //0;1;2;3;4;5;6;7;8;9;10
print(str);

Length of Array

Array.length - number of elements in Array

arr = [0,1,2,3,4,5]
print(arr.length); // 6

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