js字符串常用方法
- charAt
- length
- substr
- slice
- substring
- split
- toFixed
- toUpperCase
- toLowerCase
- concat
- startsWith
- endsWith
- trim
- indexOf
- lastIndexOf
- replace
- match
- search
- valueof
js数组常用方法
- push
- pop
- unshift
- shift
- concat
- join
- sort
- length
- reverse
- map
- forEach
- slice
- splice
- find
- every
- some
- filter
- findIndex
- fill
- reduce
- from
- of
- at
- includes
- isArray
js对象常用方法
- Object.keys()
- Object.values()
- Object.entries()
- Object.create()
- Object.assign()
- Object.seal()
- Object.freeze()
- Object.hasOwnProperty()
- delete
