Some notes on JavaScript

One, ES6

(1), New Set () is a novel data structure, similar to an array has four operation methods and four traversal methods.

Four methods of operation

• add(value): Adds a value that returns the SET structure itself.
• delete(value): Deletes a value that returns a Boolean value indicating whether the deletion was successful.
• has(value): Returns a Boolean value that indicates whether the value is a Set member.
• clear(): Clears all members without a return value.

Four traversal methods

• keys(): The iterator that returns the key name
• values(): The iterator that returns the key value
• entries(): A walker that returns a key-value pair
• forEach(): Use the callback function to traverse each member

(2) method of string

' One ' [' Length ']->3

Some notes on JavaScript