1.any 轉(zhuǎn) string
- n + ‘’ //與空字符串相加
- .toString()
- window.String()
2.any轉(zhuǎn)boolean
- !! //連續(xù)取反
- boolean()
只有5個(gè)值轉(zhuǎn)boolean時(shí)為false:0 NaN ‘’ null undefined (5個(gè)falsy值)
3.any轉(zhuǎn)number
‘1’ -> 1
- number(‘1’) === 1
- parseInt(‘1’ , 10) === 1
- parseFloat(‘1.23’) === 1.23
- ‘1’ - 0 === 1
- +‘1’ ===1