3.14: JavaScript Examples

Temperature

// 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");
}

// Checks the JavaScript environment and reads from the console, 
// the current document, or standard input as appropriate.
function input(text) {
  if (typeof console === "object") {
    return prompt(text);
  } 
  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();
  }
}

// Checks the JavaScript environment and writes to the console, 
// the current document, or standard output as appropriate.
// Reference: http://progopedia.com/example/hello-world/114/ 
function output(text) {
  if (typeof console === "object") {
    console.log(text);
  } 
  else if (typeof document === "object") {
    document.write(text);
  } 
  else {
    print(text);
  }
}

Output

Enter Fahrenheit temperature:
 100
100° Fahrenheit is 37.7777777777778° Celsius

References

• Wikiversity: Computer Programming