Methods.md

For arrays;

If a method is changing the content then it returns things other than content changed object.
If a method is not changing the content but rather change the form, and orders than the method returns reformed or ordered object.

For strings;

If not obvious, return content changed, formed, ordered final object.

Array methods;

Array methods are focused on manipulating.
slice = copy, pop = cut, shift = cut, splice = cut/paste

Example arrays

//Caller Array
var a0 = ['a', 'b', 'c', 1, 2, 3, [10,11,12, [1,2,3]], {1: "dick", 2: [1,1]}];

//Array input into method
var ia0 = ['A', 'B', 'C', 9, 8, 7, [101, 102, [103, 104]], {1: "a"}];

Methods returning elements(subset of array);

Array.pop();

Delete last element and pop it to output.

var output0 = a0.pop();
// output = { '1': 'dick', '2': [ 1, 1 ] }

var output1 = a0;
// output1 = ['a', 'b', 'c', 1, 2, 3, [10,11,12, [1,2,3]]]

Array.shift();

var output0 = a0.shift();  
// output0 = 'a'

var output1 = a0;
// output1 =
    [ 'b',
      'c',
      1,
      2,
      3,
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      { '1': 'dick', '2': [ 1, 1 ] } ]

Array.slice(begin, end);

slice = copy; caller is not affected.

var output = a0.slice(-3);
// output =
[ 3,
  [ 10, 11, 12, [ 1, 2, 3 ] ],
  { '1': 'dick', '2': [ 1, 1 ] } ]

var output = a0.slice(0,1);
// output = [ 'a' ]

Array.splice(startRemoveIndex, howManyToRemove, elementToInsert1, ..., elementToInsert2)

Returns removed part.
howManyToRemove is counting number not index number.

var output0 = a0.splice(0,2, "Removed2_Inserted1");
// output0 = [ 'a', 'b' ]

// a0 = 
    [ 'Removed2_Inserted1',
      'c',
      1,
      2,
      3,
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      { '1': 'dick', '2': [ 1, 1 ] } ]

// Assume a0 is reset.

var output1 = a0.splice(2,0, "Removed0_Inserted1", "Removed0_Inserted2");
// output1 = []

// a0 =
    [ 'a',
      'b',
      'Removed0_Inserted1',
      'Removed0_Inserted2',
      'c',
      1,
      2,
      3,
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      { '1': 'dick', '2': [ 1, 1 ] } ]

Methods returning strings;

Array.join([sep = ',']);

nested arrays are converted, nested Object is not converted.

var output = a0.join();
// output = a,b,c,1,2,3,10,11,12,1,2,3,[object Object]

Methods returning Boolean;

Methods returning Array;

Array.reverse();

var output = a0.reverse();

output =
    [ { '1': 'dick', '2': [ 1, 1 ] },
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      3,
      2,
      1,
      'c',
      'b',
      'a' ]

Methods returning Number;

Array.push(element1, ..., elementN);

Result is the pushed.length.

var output0 = a0.push(ia0);
// output0 = 9

var output1 = a0;
// output1 =
    [ 'a',
      'b',
      'c',
      1,
      2,
      3,
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      { '1': 'dick', '2': [ 1, 1 ] },
      [ 'A', 'B', 'C', 9, 8, 7, [ 101, 102, [ 103, 104 ] ], { '1': 'a' } ] ]

Array.unshift(element1, ..., elementN);

var output0 = a0.unshift("shifted1", {"shifted2": 2});
// output0 = 10

var output1 = a0;
// output1 =
    [ 'shifted1',
      { shifted2: 2 },
      'a',
      'b',
      'c',
      1,
      2,
      3,
      [ 10, 11, 12, [ 1, 2, 3 ] ],
      { '1': 'dick', '2': [ 1, 1 ] } ]

Array.length (yeah, it's not a method)

var output = a0.length;
// output = 8

Object Methods;

Methods returning arrays;

Object.keys(object)

Returns an array of object's enumerable property names. Same order as for(var i in object) loop. It's a call method.

var o0 = {0: "value1", 2: "value3", z: "value4", a: "value5", 1: "value2"};

var output = Object.keys(o0);
// output = [ '0', '1', '2', 'z', 'a' ]

String Methods;

It seems string methods are more focused on the searching ability

Example

var s0 = "apple";
var s1 = "banana";
var s2 = "tree"
var s3 = "Apple banana trees on the beach.";

Methods returning a character.

String.charAt(index)

var output = s0.charAt(9999);
// output = ''

Methods returning a String.

String.concat(string1, ..., stringN)

Do not use concat. Use assignment operator as it has better performance.

var output = s0.concat(s1, s2);
// output = 'applebananatree'

String.slice(beginSlice, endSlice)

If beginSlice is negative then beginSlice = String.leng + beginSlice.
The same goes for endSlice.

var output = s1.slice(2, -1);
// output = 'nan'

String.sub()

Return caller string with sub element surrounded

var output = s0.sub();
// output = '<sub>apple</sub>'

String.substring(start, countNumber)

If start is negative start = String.length + start. If start is negative, and abs(start) > String.length then start = 0 If countNumber is negative (or 0) it returns empty string, ''

var output = s3.substr(-6, 6);
// output = 'beach.'

String.toUpperCase()

var output = s0.toUpperCase();
// output = 'APPLE'

String.toLowerCase()

var output = s0.toLowerCase();
// output = 'apple'

Methods returning a number.

String.indexOf(searchString, fromIndex)

If "" is searched >=String.length then length of the string will be returned.
Else if characters other than "" is searched in >= String.length -1 returned.

var output = s3.indexOf("tre", 4);  
// output = 13  

String.length

var output = s3.length;
// output = 32

String.search(RegExpObject);

Versatile version of String.indexOf() method. LEARN RegEx.

Methods returning an array.

String.split(seperator, uptoCountNumber)

var output = s3.split(" ", 2);
// output = [ 'Apple', 'banana' ]