教學影片343 教學影片344 教學影片345 亂數,無條件進位ceil,捨去floor,四捨五入round 劉采雨JavaScript語言Math數學方法(內建函數) Math.random()亂數Method產生0(含)到7(不含) Math.floor()無條件捨去Method Math.ceil()進位Method Math.round()四捨Method 程式碼 <h1>劉采雨JavaScript語言Math數學方法(內建函數)</h1> <h2>Math.random()亂數Method產生0(含)到7(不含)</h2> <p id="demo"></p> <h2>Math.floor()無條件捨去Method</h2> <p id="demo1"></p> <h2>Math.ceil()進位Method</h2> <p id="demo2"></p> <h2>Math.round()四捨Method</h2> <p id="demo3"></p> <script> let y = Math.random()*7; document.getElementById("demo").innerHTML = y; document.getElementById("demo1").innerHTML = Math.floor(y); document.getElementById("demo2").innerHTML = Math.ceil(y); document.getElementById("demo3").innerHTML = Math.round(y); </script>