The String Object
Like number values, character strings also come with a useful object called the String object. Similarly, the String object provides numerous functions, methods, and properties oriented around strings.
Also similar to the Number object is the String function, which converts any passed value into a string. The String function works by calling the value's toString function, which we'll discuss a little later.
The length Property
The String object, and thus strings themselves, have only one property: the length property. As the name suggests, the length property returns the length of the string as an integer. As the indexing of a string starts at zero, the length is always one more than the last character index:
"Hello, World!".length; // => 13
The length property is particularly useful for iterating over the string, or when working with many of the string methods when its length is not already known.