14. String Object

String is an existing object in JavaScript, and below, we will show the property, and some method of string they use most often.
String Property 
Length The role is a property for download of the string.
example

String Methods
toUpperCase / toLowerCase: a role for the converted string to uppercase or lowercase.
example

substr (start, length): a string containing the start position length length it took to locate the latest. The position of the string from 0.
example

concat (string1, ...): a role for the connection string with the string.
example