锋利的ES6 — 字符串API

var str = '代码不是万能的，但不写代码是万万不能的'
str.startsWith('代码')    // true
str.startsWith('不写代码')    // false
str.startsWith('万能的', 4) // true

var str = '代码不是万能的，但不写代码是万万不能的'
str.endsWith('不能的')     // true
str.endsWith('真实')     // false
str.endsWith('万万', 16) // true

'abc'.padStart(10);         // "       abc"
'abc'.padStart(10, "foo");  // "foofoofabc"
'abc'.padStart(6,"123465"); // "123abc"
'abc'.padStart(8, "0");     // "00000abc"
'abc'.padStart(1);          // "abc"

'abc'.padEnd(10);          // "abc       "
'abc'.padEnd(10, "foo");   // "abcfoofoof"
'abc'.padEnd(6, "123456"); // "abc123"
'abc'.padEnd(1);           // "abc"

"abc".repeat(-1)     // RangeError: repeat count must be positive and less than inifinity
"abc".repeat(0)      // ""
"abc".repeat(1)      // "abc"
"abc".repeat(2)      // "abcabc"
"abc".repeat(3.5)    // "abcabcabc" 参数count将会被自动转换成整数.
"abc".repeat(1/0)    // RangeError: repeat count must be positive and less than inifinity

var username = 'dary'
var str = String.raw`hello ${username}!`
console.log(str) // hello dary!

var username = 'dary'
var age = 19
var str = String.raw({ raw: 'Hello' }, username, age)
console.log(str) // Hdarye19llo

var username = 'dary'
var age = 19
var str = String.raw({ raw: ['Hello ', ',you are ', ' years old'] }, username, age)
console.log(str) // Hello dary,you are 19 years old

str = '\u718a\u5927\u6797'

str.normalize() // 熊大林

'   Hello world!   '.trim())  // 'Hello world!'