JAVASCRIPT

js String

"Hello World"
'Hello World'
"Hello " World"
"Hello  World"
"Hello n World"
'Hello ' World'
'Hello t World'

//Concatenation
"Hello" + "World"


var x = "Hello World";

//Length of String
x.length; //It is a property

//Indexing
"Hello World"[0]
"Hello World"[3]
x = "Hello World";
x[0]
x[3]

//Immutable
x[1]
x[1] = "5"
x[1]


// return a new string, doesn't change x
//These are methods
x.slice(1, 5);
x.slice(-6, -1);
x.substr(3, 2); // 2nd parameter means the length
x.replace("Hello", "World");
x.toUpperCase();
x.toLowerCase();
x.concat("1", "2");
x.trim();


//links
//https://www.w3schools.com/jsref/jsref_obj_string.asp
//https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String

string js

const string1 = "A string primitive";
const string2 = 'Also a string primitive';
const string3 = `Yet another string primitive`;
const string4 = new String("A String object");

Stringy.JS

StringyJS is a free open-source javascript string methods extension library: 
https://github.com/Adison-Masih/Stringy

js string

var myString = "foobar";
//Can use single quotes, double quotes, or backticks for template literals.