Differences between Java, C # and JavaScript (how to determine the degree of obesity)

I understand Java and C #, but as for JavaScript, it ended up flowing, so I output it to look back.

BMI is Weight (kg) / (height (m) * height (m)) Is required by.

[Execution example]

Weight (kg)> 70.2 Height (cm)> 175.2 Your BMI is 22.87.

If you ask for this in the following languages ...

Java (console)

Example

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        System.out.print("body weight(kg)>");
        double weight=sc.nextDouble();
        System.out.print("height(cm)>");
        double height=sc.nextDouble();
        //Convert cm to m
        height/=100; 
        double bmi=weight/(height*height);
        System.out.printf("Your BMI%.It is 2f.",bmi);
    }
}

I think there are simply other ways.

C # (console)

Example

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BmiApp {
    class Program {
        static void Main(string[] args) {
            Console.Write("height(cm)>");
            var height = float.Parse(Console.ReadLine());
            Console.Write("body weight(kg)>");
            var weight = float.Parse(Console.ReadLine());
            CalcBMI(height, weight, out float bmi, out string result);
            Console.WriteLine($"height:{height}cm,body weight:{weight}kg your BMI{bmi:F2}。\n{result}is");
        }
        static void CalcBMI(float heightCm,float weightKg,out float bmi,out string result) {
            bmi = weightKg / (heightCm / 100 * heightCm / 100);
            if (bmi >= 25.0f) {
                result = "obesity";
            }else if(bmi >=18.5f) {
                result = "Standard weight";
            } else {
                result = "Skinny type";
            }
        }
    }
}

Method carved version Personally, I feel that C # is made by taking advantage of other languages.

@albireo's refactoring example

using System;

namespace BmiApp {
    class Program {
        static void Main(string[] args) {
            Console.Write("height(cm)>");
            var height = float.Parse(Console.ReadLine());
            Console.Write("body weight(kg)>");
            var weight = float.Parse(Console.ReadLine());
            var (bmi, result) = CalcBMI(height/100, weight);
            Console.WriteLine($"height:{height}cm,body weight:{weight}kg your BMI{bmi:F2}。\n{result}is");
        }
        static (float, string) CalcBMI(float height, float weight) {
            float bmi = weight / (height * height);
            if (bmi >= 25.0f) {
                return (bmi, "obesity");
            }else if(bmi >=18.5f) {
                return (bmi, "Standard weight");
            } else {
                return (bim, "Skinny type");
            }
        }
    }
}

Version using Value Tuple informative.

JavaScript(Jsp)

Example

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="utf-8">
    <title>title</title>
</head>
<body>
height(cm):<input type="number" step="0.1" min="0" id="height"><br>
body weight(kg):<input type="number" step="0.1" min="0" id="weight"><br>
    <button id="bt">measurement</button>
    <div id="bmi"></div>
    <div id="result"></div>

<script>
//strict mode (strict mode):To Java Like//
/*Because more accurate error checking is performed
Ambiguous implementations that previously did not result in an error are treated as an error.*/
//Even if the expression is ambiguous ... How to write depends on the person
'use strict';
//Load Html and then execute
window.onload=function(){
    //Get Dom:
    const eleHeight=document.getElementById("height");
    const eleWeight=document.getElementById("weight");
    const eleBt=document.getElementById("bt");
    const eleBmi=document.getElementById("bmi");
    const eleResult=document.getElementById("result");
    eleBt.addEventListener("click",function(){
        //Flot conversion//
        let height=parseFloat(eleHeight.value)/100;
        let weight=parseFloat(eleWeight.value);
        let bmi=weight/(height*height);
        //toFixed two decimal places//
        eleBmi.textContent='BMI:'+bmi.toFixed(2); 
        let result;
        if(bmi<18.5){
            result='Underweight';
        }else if(bmi<25){
            result='usually';
        }else if(bmi<30){
            result='obesity(Once)';
        }else if(bmi<35){
            result='obesity(Twice)';
        }else if(bmi<40){
            result='obesity(3 times)';
        }else{
            result='obesity(4 degrees)';
        }
        ////Set text content////
        eleResult.textContent=result;
    });
}
</script>
</body>
</html>

@albireo's refactoring example

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="utf-8">
    <title>title</title>
    <script>
    'use strict';
    //Execute by clicking the measurement button
    function CalcBMI(){
        //Flot conversion//
        let height=parseFloat(document.getElementById('height').value)/100;
        let weight=parseFloat(document.getElementById('weight').value);
        //toFixed two decimal places//
        let bmi=weight/(height*height).toFixed(2);
        document.getElementById("bmi").textContent='BMI:'+bmi;
        let result = '';
        if(bmi<18.5){
            result='Underweight';
        }else if(bmi<25){
            result='usually';
        }else if(bmi<30){
            result='obesity(Once)';
        }else if(bmi<35){
            result='obesity(Twice)';
        }else if(bmi<40){
            result='obesity(3 times)';
        }else{
            result='obesity(4 degrees)';
        }
        ////Set text content////
        document.getElementById("result").textContent=result;
    }
    </script>
</head>
<body>
height(cm):<input type="number" step="0.1" min="0" id="height"><br>
body weight(kg):<input type="number" step="0.1" min="0" id="weight"><br>
    <button id="bt" onclick="CalcBMI()">measurement</button>
    <div id="bmi"></div>
    <div id="result"></div>
</body>
</html>

It's going to be pretty simple If you think

@htsign says that document.getElementById (id) .valueAsNumber is better than parseFloat (document.getElementById (id) .value).

informative. Thank you to both of you.