Calculate the volume of a cylinder with javascript and keep 4 decimal places-JS Tutorial-php.cn

Calculate the volume of a cylinder with javascript and keep 4 decimal places

藏色散人

Release： 2021-08-12 15:06:04

Original

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Do you still remember the formula for the volume of a cylinder? Today we will introduce to you how to calculate the volume of a cylinder through JavaScript and keep 4 decimal places~

First of all, let’s recall the formula for the volume of a cylinder:

Volume of a cylinder = base area , or

v=1/2ch×r (half of the side area × radius)

Calculate the volume of a cylinder with javascript and keep 4 decimal places

Now I will start the important content of this article!

Go directly to the code:

<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
    <script>
        function Cylinder(cyl_height, cyl_diameter) {
            this.cyl_height = cyl_height;
            this.cyl_diameter = cyl_diameter;
        }

        Cylinder.prototype.Volume = function () {
            var radius = this.cyl_diameter / 2;
            return this.cyl_height * Math.PI * radius * radius;
        };

        var cyl = new Cylinder(7, 4);
        
        console.log(&#39;体积 =&#39;, cyl.Volume().toFixed(4));
    </script>
</head>
<body>
</body>
</html>

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The calculation result is:

Note:

PI attribute is π, that is The ratio of the circumference of a circle to its diameter. This value is approximately 3.141592653589793. Its syntax is "Math.PI". Calculate the volume of a cylinder with javascript and keep 4 decimal places

The prototype attribute gives you the ability to add properties and methods to an object with the syntax "object.prototype.name=value".

The console.log() method is used to output information on the console. This method is very helpful for testing the development process. During the test of this method, the console needs to be visible (press F12 to open the browser console).

→With an introduction to π:

Pi (π) is the ratio of the circumference to the diameter of a circle. It is generally represented by the Greek letter π and is used in mathematics and physics. A universal mathematical constant. π is also equal to the ratio of the area of a circle to the square of its radius. It is also a key value for accurately calculating geometric shapes such as circle circumference, circle area, and sphere volume. And in analysis, π can be defined very strictly as the smallest positive real number x that satisfies sinx = 0.

Finally, I would like to recommend "JavaScript Basics Tutorial

" ~ Welcome everyone to learn ~

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