JavaScript Strings Basic Info and String Concatenation
Example
Strings in JavaScript can be enclosed in Single quotes 'hello', Double quotes "Hello" and (from ES2015, ES6) in Template Literals (backticks) `hello`.
var hello = "Hello";
var world = 'world';
var helloW = `Hello World`; // ES2015 / ES6
Strings can be created from other types using the String() function.
var intString = String(32); // "32"
var booleanString = String(true); // "true"
var nullString = String(null); // "null"
Or, toString() can be used to convert Numbers, Booleans or Objects to Strings.
var intString = (5232).toString(); // "5232"
var booleanString = (false).toString(); // "false"
var objString = ({}).toString(); // "[object Object]"
Strings also can be created by using String.fromCharCode method.
String.fromCharCode(104,101,108,108,111) //"hello"
Creating a String object using new keyword is allowed, but is not recommended as it behaves like Objects unlike primitive strings.
var objectString = new String("Yes, I am a String object");
typeof objectString;//"object"
typeof objectString.valueOf();//"string"
Concatenating Strings
String concatenation can be done with the + concatenation operator, or with the built-in concat() method on the String object prototype.
var foo = "Foo";
var bar = "Bar";
console.log(foo + bar); // => "FooBar"
console.log(foo + " " + bar); // => "Foo Bar"
foo.concat(bar) // => "FooBar"
"a".concat("b", " ", "d") // => "ab d"
Strings can be concatenated with non-string variables but will type-convert the non-string variables into strings.
var string = "string";
var number = 32;
var boolean = true;
console.log(string + number + boolean); // "string32true"
String Templates
6
Strings can be created using template literals (backticks) `hello`.
var greeting = `Hello`;
With template literals, you can do string interpolation using ${variable} inside template literals:
var place = `World`;
var greet = `Hello ${place}!`
console.log(greet); // "Hello World!"
You can use String.raw to get backslashes to be in the string without modification.
`a\\b` // = a\b
String.raw`a\\b` // = a\\b
