<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <script> console.log(Math.abs(-100)) // 100 #绝对值 console.log(Math.ceil(3.14)) //4 #向上取整 console.log(Math.floor(3.94)) //3 #向下取整 console.log(Math.round(3.94)) //4 #四舍五入 console.log(Math.round(3.14)) //3 #四舍五入 // 0-100随机浮点数 console.log(Math.round(Math.random()*100)) </script> </head> <body> <h1>welcome to JS!</h1> </body> </html>