//https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
//返回對應索引的字符
chartAt()
//返回對應所引的字符的統一碼(Unicode value)
charCodeAt()
//Returns a non-negative integer that is the UTF-16 encoded code point value at the given position.
codePointAt();
//拼接兩個字符串,並返回一個新的字符串
concat();
//Determines whether one string may be found within another string.
includes();
//Determines whether a string ends with the characters of another string.
endsWidth();
//返回一個字符串在另外一個字符串中首次出現的位置,若是查找不到,返回-1
indexOf();
//返回一個字符串在另外一個字符串中末次出現的位置,若是查找不到,返回-1
lastIndexOf();
//Returns a number indicating whether a reference string comes before or after or is the same as the given string in sort order.
localeCompare();
//用字符串匹配一個字符串
mach();
//Returns the Unicode Normalization Form of the calling string value.
normalize();
//Returns a string consisting of the elements of the object repeated the given times.
repeat();
//找出字符串中和正則表達式匹配的部分,並用一個新的子串替換
replace();
//找出字符串中和正則表達式匹配的部分
search();
//截取字符串的一部分返回
slice();
//把一個字符串分割成數組,分割點爲傳入的子串
split();
//Returns the characters in a string beginning at the specified location through the specified number of characters.
substr();
//
substring();
//
toLocalLowerCase();
//
toLocalUpperCase();
toLowerCase();
toSource();
toString();
toUpperCase();
trim();
valueOf();