String Object Functions
String is a built-in type in JavaScript. It holds a sequence of characters in the Unicode character set. A string literal is created using a double quote or a single quote strings.
var txt = 'Hello world'; // or "Hello world"
Two strings can be concatenated by using the + operator, as well as by using the concat function. For example:
var txt = "Hello " + 'world';
field['Salesperson.First Name'].concat(" ",field['Salesperson.Last Name'])
The following topics describe common string functions. Consult a JavaScript reference such as W3Schools.com for details about other string functions.