A JavaScript string stores a series of characters like "John Doe".
A string can be any text inside double or single quotes.
Primitive values, like "John Doe", cannot have properties or methods (because they are not objects).
But with JavaScript, methods and properties are also available to primitive values, because JavaScript treats primitive values as objects when executing methods and properties.
constructor Returns the string's constructor function length Returns the length of a string prototype Allows you to add properties and methods to an object
All string methods return a new value. They do not change the original variable.
charAt() Returns the character at the specified index (position) charCodeAt() Returns the Unicode of the character at the specified index concat() Joins two or more strings, and returns a new joined strings endsWith() Checks whether a string ends with specified string/characters fromCharCode() Converts Unicode values to characters includes() Checks whether a string contains the specified string/characters indexOf() Returns the position of the first found occurrence of a specified value in a string lastIndexOf() Returns the position of the last found occurrence of a specified value in a string localeCompare() Compares two strings in the current locale match() Searches a string for a match against a regular expression, and returns the matches repeat() Returns a new string with a specified number of copies of an existing string replace() Searches a string for a specified value, or a regular expression, and returns a new string where the specified values are replaced
search() Searches a string for a specified value, or regular expression, and returns the position of the match slice() Extracts a part of a string and returns a new string split() Splits a string into an array of substrings startsWith() Checks whether a string begins with specified characters substr() Extracts the characters from a string, beginning at a specified start position, and through the specified number of character
substring() Extracts the characters from a string, between two specified indices toLocaleLowerCase() Converts a string to lowercase letters, according to the host's locale toLocaleUpperCase() Converts a string to uppercase letters, according to the host's locale toLowerCase() Converts a string to lowercase letters toString() Returns the value of a String object toUpperCase() Converts a string to uppercase letters trim() Removes whitespace from both ends of a string valueOf() Returns the primitive value of a String object
good reference: https://www.w3schools.com/jsref/jsref_obj_string.asp