parseInt(5/2) 2 ;
praseFloat() //取幅点型
4舍5入的是Math.round(xxxxxxxx) Math.round(1.4) 1 Math.round(1.5) 2
取下限是Math.floor(xxxxxxxxx) Math.floor(1.1) 1
取上限是Math.ceil(xxxxxxxx) Math.ceil(1.1) 2
parseInt(5/2) 2 ;
praseFloat() //取幅点型
4舍5入的是Math.round(xxxxxxxx) Math.round(1.4) 1 Math.round(1.5) 2
取下限是Math.floor(xxxxxxxxx) Math.floor(1.1) 1
取上限是Math.ceil(xxxxxxxx) Math.ceil(1.1) 2