蔡子霖W3SCHOOL物件OBJECT亂數RANDOM進位CEIL捨去FLOOPR

教學影片343

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亂數,無條件進位ceil,捨去floor,四捨五入round

蔡子霖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>蔡子霖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>