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Engineering LibreTexts

3.14: JavaScript Examples

  • Page ID
    10633
  • 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