Applied Programming/Functions/JavaScript
functions.js
edit/* This program converts a Fahrenheit temperature to Celsius.
Input:
Fahrenheit temperature
Output:
Fahrenheit temperature
Celsius temperature
Example:
Enter Fahrenheit temperature: 100
100° Fahrenheit is 37.77777777777778° Celsius
References:
* http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html
* https://javascript.info/comments
* http://www.mathsisfun.com/temperature-conversion.html
*/
const TEMPERATURE_DIFFERENCE = 32;
const TEMPERATURE_RATIO = 5 / 9;
main();
/**
* Runs main program logic.
*/
function main() {
let fahrenheit = getFahrenheit();
let celsius = calculateCelsius(fahrenheit);
displayResults(fahrenheit, celsius);
}
/**
* Gets Fahrenheit temperature.
*
* @returns {number} Fahrenheit temperature
*/
function getFahrenheit() {
let fahrenheit = input("Enter Fahrenheit temperature: ");
return fahrenheit;
}
/**
* Converts Fahrenheit temperature to Celsius.
*
* @param {number} Fahrenheit temperature
* @returns {number} Celsius temperature
*/
function calculateCelsius(fahrenheit) {
let celsius = (fahrenheit - TEMPERATURE_DIFFERENCE) * TEMPERATURE_RATIO;
return celsius;
}
/**
* Displays Fahrenheit and Celsius temperatures.
*
* @param {number} Fahrenheit temperature
* @param {number} Celsius temperature
*/
function displayResults(fahrenheit, celsius) {
output(`${fahrenheit}° Fahrenheit is ${celsius}° Celsius`);
}
/**
* Generic input function to get input in HTML, Node, or Rhino environments.
*
* @param {string} text prompt
* @returns {string} input
*/
function input(text) {
if (typeof window === 'object') {
return prompt(text)
}
else if (typeof console === 'object') {
const rls = require('readline-sync');
let value = rls.question(text);
return value;
}
else {
output(text);
let isr = new java.io.InputStreamReader(java.lang.System.in);
let br = new java.io.BufferedReader(isr);
let line = br.readLine();
return line.trim();
}
}
/**
* Generic output function to display output in HTML, Node, or Rhino environments.
*
* @param {string} text prompt
* @returns {string} input
*/
function output(text) {
if (typeof document === 'object') {
document.write(text);
}
else if (typeof console === 'object') {
console.log(text);
}
else {
print(text);
}
}
Try It
editCopy and paste the code above into one of the following free online development environments or use your own JavaScript compiler / interpreter / IDE.