Programming Fundamentals/Functions/JavaScript

functions.js

// This program asks the user for a Fahrenheit temperature,
// converts the given temperature to Celsius,
// and displays the results.
//
// References:
// https://www.mathsisfun.com/temperature-conversion.html
// https://en.wikibooks.org/wiki/JavaScript

main();

function main() {
  var fahrenheit = getFahrenheit();
  var celisus = calculateCelsius(fahrenheit);
  displayResult(fahrenheit, celisus);
}

function getFahrenheit() {
  var fahrenheit = input("Enter Fahrenheit temperature:");
  return fahrenheit;
}

function calculateCelsius(fahrenheit) {
  var celisus = (fahrenheit - 32) * 5 / 9;
  return celisus;
}

function displayResult(fahrenheit, celisus) {
  output(fahrenheit + "° Fahrenheit is " + 
    celisus + "° Celsius");
}

function input(text) {
  if (typeof window === 'object') {
    return prompt(text)
  }
  else if (typeof console === 'object') {
    const rls = require('readline-sync');
    var value = rls.question(text);
    return value;
  }
  else {
    output(text);
    var isr = new java.io.InputStreamReader(java.lang.System.in); 
    var br = new java.io.BufferedReader(isr); 
    var line = br.readLine();
    return line.trim();
  }
}

function output(text) {
  if (typeof document === 'object') {
    document.write(text);
  } 
  else if (typeof console === 'object') {
    console.log(text);
  } 
  else {
    print(text);
  }
}

Try It

Copy and paste the code above into one of the following free online development environments or use your own JavaScript compiler / interpreter / IDE.

functions.js

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