var random1 = Math.random()*10 // 0~10,10不可以取
var interA3 = Math.round(random1) // 四舍五入
var interB3 = Math.ceil(random1) // 向上取整
var interC3 = Math.floor(random1) // 向下取整
var interD3 = random1.toFixed(2)
console.log('随机数random1=',random1)
console.log('四舍五入interA3=',interA3)
console.log('向上取整interB3=',interB3)
console.log('向下取整interC3=',interC3)
console.log('保留两位有效小数interD3=',interD3)
