var length // A nonzero-based integer specifying the number of characters in the specified string.
function charAt(index) // Returns the character at the position specified by the "index" parameter, or returns an empty string if "index" is not a number from 0 to "string.length - 1".
function charCodeAt(index) // Returns a 16-bit integer from 0 to 65535 that represents the character specified by the "index" parameter, or returns "NaN" if "index" is not a number from 0 to "string.length - 1".
function concat(value) // Combines the value of the String object with the values in the parameters and returns the newly formed string; the original value, my_str, is unchanged.
function fromCharCode(c) // Returns a string made up of the characters represented by the ASCII values in the parameters.
function indexOf(substring, startIndex) // Returns the position of the first occurrence of substring found at or after "startIndex" within the calling string, or returns -1 if "substring" is not found.
function lastIndexOf(substring, startIndex) // Searches the string from right to left and returns the index of the last occurrence of "substring" found before "startIndex" within the calling string, or returns -1 if "substring" is not found.
function slice(start, end) // Returns a string that includes the "start" character and all characters up to the "end" character(not including it).
function split(delimiter, limit) // Splits a String object into substrings by breaking it where the specified "delimiter" parameter occurs, and returns the substrings in an array.
function substr(start, length) // Returns the characters in a string from the starting point specified in the "start" parameter through the number of characters specified in the "length" parameter.
function substring(start, end) // Returns a string consisting of the characters between the points specified by the "start" and "end" parameters.
function toLowerCase() // Returns a string, with all of the uppercase characters converted to lowercase. The original value is unchanged.
function toUpperCase() // Returns a string, with all of the lowercase characters converted to uppercase. The original value is unchanged.
