BMIの判定器 【JavaScriptのサンプルコード】
山崎講師
ここでは、当社の新人研修受講者に向けて、JavaScriptのサンプルコードを紹介しています。
BMIの判定器のサンプルコード
身長と体重からBMI（Body Mass Index）を判定します。
<!DOCTYPE html>
<html>
<head>
<title>BMI</title>
<meta charset="UTF-8">
<script>
function calculate() {
var h = document.getElementById("height").value;
var w = document.getElementById("weight").value;
var r = Math.round((w / (h * h)) * 10) / 10;
var comment;
var color;
if (Number.isNaN(r)) {
comment = " please enter correctly ";
color = "red";
} else if (r < 18.5) {
comment = " You are in the underweight.";
color = "blue";
} else if (r < 25) {
comment = " You are in the normal range.";
color = "green";
} else {
comment = " You are in the overweight.";
color = "yello";
}
document.getElementById('result').style.color = color;
document.getElementById('result').textContent = "Your BMI is " + r + comment;
}
</script>
</head>
<body>
<h1>Body Mass Index</h1>
Height(m):<input id ="height"/><br>
Weight(kg):<input id ="weight"/><br>
<p><button onclick="calculate()">calculate</button></p>
<p id ="result" ></p>
</body>
</html>
