Looking for javascript Answers? Try Ask4KnowledgeBase
Looking for javascript Keywords? Try Ask4Keywords

JavaScript Basic Info and String Concatenation


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


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